File cli-0001-docs-include-required-tools-in-source-... of Package docker

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File cli-0001-docs-include-required-tools-in-source-tree.patch of Package docker (Revision 21792492e8ab20f60c746145f30a6d4c)

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From b58b0cfe39ec00365ef260ee5758eca9b4fac099 Mon Sep 17 00:00:00 2001
From: danishprakash <danish.prakash@suse.com>
Date: Mon, 12 Feb 2024 18:07:06 +0530
Subject: [PATCH] docs: include required tools in source tree

In order to be able to build the documentation without internet access
(as is required by some distribution build systems), all of the source
code needed for the build needs to be available in the source tarball.

This used to be possible with the docker-cli sources but was
accidentally broken with some CI changes that switched to downloading
the tools (by modifying go.mod as part of the docs build script).

This pattern also maked documentation builds less reproducible since the
tool version used was not based on the source code version.

Fixes: commit 7dc35c03fca5 ("validate manpages target")
Fixes: commit a650f4ddd008 ("switch to cli-docs-tool for yaml docs generation")
Signed-off-by: Aleksa Sarai <asarai@suse.de>
---
 docs/generate/go.mod                          |   13 -
 docs/generate/tools.go                        |    8 -
 import.go                                     |   17 +
 man/tools.go                                  |   11 -
 scripts/docs/generate-man.sh                  |   33 +-
 scripts/docs/generate-md.sh                   |   36 +-
 scripts/docs/generate-yaml.sh                 |   29 +-
 vendor.mod                                    |    5 +
 vendor.sum                                    |    4 +
 .../cpuguy83/go-md2man/v2/.gitignore          |    2 +
 .../cpuguy83/go-md2man/v2/.golangci.yml       |    6 +
 .../cpuguy83/go-md2man/v2/Dockerfile          |   20 +
 .../cpuguy83/go-md2man/v2/LICENSE.md          |   21 +
 .../github.com/cpuguy83/go-md2man/v2/Makefile |   35 +
 .../cpuguy83/go-md2man/v2/README.md           |   15 +
 .../cpuguy83/go-md2man/v2/go-md2man.1.md      |   28 +
 .../cpuguy83/go-md2man/v2/md2man.go           |   53 +
 .../cpuguy83/go-md2man/v2/md2man/md2man.go    |   16 +
 .../cpuguy83/go-md2man/v2/md2man/roff.go      |  348 ++
 .../docker/cli-docs-tool/.dockerignore        |    2 +
 .../docker/cli-docs-tool/.gitignore           |    2 +
 .../docker/cli-docs-tool/.golangci.yml        |   37 +
 .../docker/cli-docs-tool/Dockerfile           |   86 +
 .../github.com/docker/cli-docs-tool/LICENSE   |  202 ++
 .../github.com/docker/cli-docs-tool/README.md |   67 +
 .../cli-docs-tool/annotation/annotation.go    |   25 +
 .../docker/cli-docs-tool/clidocstool.go       |  123 +
 .../docker/cli-docs-tool/clidocstool_md.go    |  280 ++
 .../docker/cli-docs-tool/clidocstool_yaml.go  |  435 +++
 .../docker/cli-docs-tool/docker-bake.hcl      |   51 +
 .../docker/cli-docs-tool/markdown.go          |   87 +
 .../russross/blackfriday/v2/.gitignore        |    8 +
 .../russross/blackfriday/v2/.travis.yml       |   17 +
 .../russross/blackfriday/v2/LICENSE.txt       |   29 +
 .../russross/blackfriday/v2/README.md         |  335 ++
 .../russross/blackfriday/v2/block.go          | 1612 +++++++++
 .../github.com/russross/blackfriday/v2/doc.go |   46 +
 .../russross/blackfriday/v2/entities.go       | 2236 ++++++++++++
 .../github.com/russross/blackfriday/v2/esc.go |   70 +
 .../russross/blackfriday/v2/html.go           |  952 ++++++
 .../russross/blackfriday/v2/inline.go         | 1228 +++++++
 .../russross/blackfriday/v2/markdown.go       |  950 ++++++
 .../russross/blackfriday/v2/node.go           |  360 ++
 .../russross/blackfriday/v2/smartypants.go    |  457 +++
 vendor/github.com/spf13/cobra/doc/man_docs.go |  246 ++
 vendor/github.com/spf13/cobra/doc/md_docs.go  |  158 +
 .../github.com/spf13/cobra/doc/rest_docs.go   |  186 +
 vendor/github.com/spf13/cobra/doc/util.go     |   52 +
 .../github.com/spf13/cobra/doc/yaml_docs.go   |  175 +
 vendor/gopkg.in/yaml.v3/LICENSE               |   50 +
 vendor/gopkg.in/yaml.v3/NOTICE                |   13 +
 vendor/gopkg.in/yaml.v3/README.md             |  150 +
 vendor/gopkg.in/yaml.v3/apic.go               |  747 ++++
 vendor/gopkg.in/yaml.v3/decode.go             | 1000 ++++++
 vendor/gopkg.in/yaml.v3/emitterc.go           | 2020 +++++++++++
 vendor/gopkg.in/yaml.v3/encode.go             |  577 ++++
 vendor/gopkg.in/yaml.v3/parserc.go            | 1258 +++++++
 vendor/gopkg.in/yaml.v3/readerc.go            |  434 +++
 vendor/gopkg.in/yaml.v3/resolve.go            |  326 ++
 vendor/gopkg.in/yaml.v3/scannerc.go           | 3038 +++++++++++++++++
 vendor/gopkg.in/yaml.v3/sorter.go             |  134 +
 vendor/gopkg.in/yaml.v3/writerc.go            |   48 +
 vendor/gopkg.in/yaml.v3/yaml.go               |  698 ++++
 vendor/gopkg.in/yaml.v3/yamlh.go              |  807 +++++
 vendor/gopkg.in/yaml.v3/yamlprivateh.go       |  198 ++
 vendor/modules.txt                            |   15 +
 66 files changed, 22631 insertions(+), 96 deletions(-)
 delete mode 100644 docs/generate/go.mod
 delete mode 100644 docs/generate/tools.go
 create mode 100644 import.go
 delete mode 100644 man/tools.go
 create mode 100644 vendor/github.com/cpuguy83/go-md2man/v2/.gitignore
 create mode 100644 vendor/github.com/cpuguy83/go-md2man/v2/.golangci.yml
 create mode 100644 vendor/github.com/cpuguy83/go-md2man/v2/Dockerfile
 create mode 100644 vendor/github.com/cpuguy83/go-md2man/v2/LICENSE.md
 create mode 100644 vendor/github.com/cpuguy83/go-md2man/v2/Makefile
 create mode 100644 vendor/github.com/cpuguy83/go-md2man/v2/README.md
 create mode 100644 vendor/github.com/cpuguy83/go-md2man/v2/go-md2man.1.md
 create mode 100644 vendor/github.com/cpuguy83/go-md2man/v2/md2man.go
 create mode 100644 vendor/github.com/cpuguy83/go-md2man/v2/md2man/md2man.go
 create mode 100644 vendor/github.com/cpuguy83/go-md2man/v2/md2man/roff.go
 create mode 100644 vendor/github.com/docker/cli-docs-tool/.dockerignore
 create mode 100644 vendor/github.com/docker/cli-docs-tool/.gitignore
 create mode 100644 vendor/github.com/docker/cli-docs-tool/.golangci.yml
 create mode 100644 vendor/github.com/docker/cli-docs-tool/Dockerfile
 create mode 100644 vendor/github.com/docker/cli-docs-tool/LICENSE
 create mode 100644 vendor/github.com/docker/cli-docs-tool/README.md
 create mode 100644 vendor/github.com/docker/cli-docs-tool/annotation/annotation.go
 create mode 100644 vendor/github.com/docker/cli-docs-tool/clidocstool.go
 create mode 100644 vendor/github.com/docker/cli-docs-tool/clidocstool_md.go
 create mode 100644 vendor/github.com/docker/cli-docs-tool/clidocstool_yaml.go
 create mode 100644 vendor/github.com/docker/cli-docs-tool/docker-bake.hcl
 create mode 100644 vendor/github.com/docker/cli-docs-tool/markdown.go
 create mode 100644 vendor/github.com/russross/blackfriday/v2/.gitignore
 create mode 100644 vendor/github.com/russross/blackfriday/v2/.travis.yml
 create mode 100644 vendor/github.com/russross/blackfriday/v2/LICENSE.txt
 create mode 100644 vendor/github.com/russross/blackfriday/v2/README.md
 create mode 100644 vendor/github.com/russross/blackfriday/v2/block.go
 create mode 100644 vendor/github.com/russross/blackfriday/v2/doc.go
 create mode 100644 vendor/github.com/russross/blackfriday/v2/entities.go
 create mode 100644 vendor/github.com/russross/blackfriday/v2/esc.go
 create mode 100644 vendor/github.com/russross/blackfriday/v2/html.go
 create mode 100644 vendor/github.com/russross/blackfriday/v2/inline.go
 create mode 100644 vendor/github.com/russross/blackfriday/v2/markdown.go
 create mode 100644 vendor/github.com/russross/blackfriday/v2/node.go
 create mode 100644 vendor/github.com/russross/blackfriday/v2/smartypants.go
 create mode 100644 vendor/github.com/spf13/cobra/doc/man_docs.go
 create mode 100644 vendor/github.com/spf13/cobra/doc/md_docs.go
 create mode 100644 vendor/github.com/spf13/cobra/doc/rest_docs.go
 create mode 100644 vendor/github.com/spf13/cobra/doc/util.go
 create mode 100644 vendor/github.com/spf13/cobra/doc/yaml_docs.go
 create mode 100644 vendor/gopkg.in/yaml.v3/LICENSE
 create mode 100644 vendor/gopkg.in/yaml.v3/NOTICE
 create mode 100644 vendor/gopkg.in/yaml.v3/README.md
 create mode 100644 vendor/gopkg.in/yaml.v3/apic.go
 create mode 100644 vendor/gopkg.in/yaml.v3/decode.go
 create mode 100644 vendor/gopkg.in/yaml.v3/emitterc.go
 create mode 100644 vendor/gopkg.in/yaml.v3/encode.go
 create mode 100644 vendor/gopkg.in/yaml.v3/parserc.go
 create mode 100644 vendor/gopkg.in/yaml.v3/readerc.go
 create mode 100644 vendor/gopkg.in/yaml.v3/resolve.go
 create mode 100644 vendor/gopkg.in/yaml.v3/scannerc.go
 create mode 100644 vendor/gopkg.in/yaml.v3/sorter.go
 create mode 100644 vendor/gopkg.in/yaml.v3/writerc.go
 create mode 100644 vendor/gopkg.in/yaml.v3/yaml.go
 create mode 100644 vendor/gopkg.in/yaml.v3/yamlh.go
 create mode 100644 vendor/gopkg.in/yaml.v3/yamlprivateh.go

diff --git a/docs/generate/go.mod b/docs/generate/go.mod
deleted file mode 100644
index d62ff455713a..000000000000
--- a/docs/generate/go.mod
+++ /dev/null
@@ -1,13 +0,0 @@
-module github.com/docker/cli/docs/generate
-
-// dummy go.mod to avoid dealing with dependencies specific
-// to docs generation and not really part of the project.
-
-go 1.16
-
-//require (
-//	github.com/docker/cli v0.0.0+incompatible
-//	github.com/docker/cli-docs-tool v0.5.0
-//)
-//
-//replace github.com/docker/cli v0.0.0+incompatible => ../../
diff --git a/docs/generate/tools.go b/docs/generate/tools.go
deleted file mode 100644
index 47510bc49a89..000000000000
--- a/docs/generate/tools.go
+++ /dev/null
@@ -1,8 +0,0 @@
-//go:build tools
-// +build tools
-
-package main
-
-import (
-	_ "github.com/docker/cli-docs-tool"
-)
diff --git a/import.go b/import.go
new file mode 100644
index 000000000000..662a6055146c
--- /dev/null
+++ b/import.go
@@ -0,0 +1,17 @@
+// This is only used to define imports we need for doc generation.
+
+//go:build never
+// +build never
+
+package cli
+
+import (
+	// Used for md and yaml doc generation.
+	_ "github.com/docker/cli-docs-tool"
+
+	// Used for man page generation.
+	_ "github.com/cpuguy83/go-md2man/v2"
+	_ "github.com/spf13/cobra"
+	_ "github.com/spf13/cobra/doc"
+	_ "github.com/spf13/pflag"
+)
diff --git a/man/tools.go b/man/tools.go
deleted file mode 100644
index 3cafe6533aff..000000000000
--- a/man/tools.go
+++ /dev/null
@@ -1,11 +0,0 @@
-//go:build tools
-// +build tools
-
-package main
-
-import (
-	_ "github.com/cpuguy83/go-md2man/v2"
-	_ "github.com/spf13/cobra"
-	_ "github.com/spf13/cobra/doc"
-	_ "github.com/spf13/pflag"
-)
diff --git a/scripts/docs/generate-man.sh b/scripts/docs/generate-man.sh
index 12a4b81199db..1e12a95e9c9a 100755
--- a/scripts/docs/generate-man.sh
+++ b/scripts/docs/generate-man.sh
@@ -1,35 +1,22 @@
 #!/usr/bin/env bash
 
-set -eu
-
-: "${MD2MAN_VERSION=v2.0.3}"
+set -Eeuo pipefail
 
 export GO111MODULE=auto
 
-function clean {
-  rm -rf "$buildir"
+# temporary "go.mod" to make -modfile= work
+touch go.mod
+
+function clean() {
+  rm -f "$(pwd)/go.mod"
 }
 
-buildir=$(mktemp -d -t docker-cli-docsgen.XXXXXXXXXX)
 trap clean EXIT
 
-(
-  set -x
-  cp -r . "$buildir/"
-  cd "$buildir"
-  # init dummy go.mod
-  ./scripts/vendor init
-  # install go-md2man and copy man/tools.go in root folder
-  # to be able to fetch the required dependencies
-  go mod edit -modfile=vendor.mod -require=github.com/cpuguy83/go-md2man/v2@${MD2MAN_VERSION}
-  cp man/tools.go .
-  # update vendor
-  ./scripts/vendor update
-  # build gen-manpages
-  go build -mod=vendor -modfile=vendor.mod -tags manpages -o /tmp/gen-manpages ./man/generate.go
-  # build go-md2man
-  go build -mod=vendor -modfile=vendor.mod -o /tmp/go-md2man ./vendor/github.com/cpuguy83/go-md2man/v2
-)
+# build gen-manpages
+go build -mod=vendor -modfile=vendor.mod -tags manpages -o /tmp/gen-manpages ./man/generate.go
+# build go-md2man
+go build -mod=vendor -modfile=vendor.mod -o /tmp/go-md2man ./vendor/github.com/cpuguy83/go-md2man/v2
 
 mkdir -p man/man1
 (set -x ; /tmp/gen-manpages --root "." --target "$(pwd)/man/man1")
diff --git a/scripts/docs/generate-md.sh b/scripts/docs/generate-md.sh
index 4caa01eaed23..0af86843bbe4 100755
--- a/scripts/docs/generate-md.sh
+++ b/scripts/docs/generate-md.sh
@@ -1,33 +1,29 @@
 #!/usr/bin/env bash
 
-set -eu
-
-: "${CLI_DOCS_TOOL_VERSION=v0.7.0}"
+set -Eeuo pipefail
 
 export GO111MODULE=auto
 
+# temporary "go.mod" to make -modfile= work
+touch go.mod
+
 function clean {
-  rm -rf "$buildir"
+  rm -f "$(pwd)/go.mod"
+  if [ -f "$(pwd)/docs/reference/commandline/docker.md" ]; then
+    mv "$(pwd)/docs/reference/commandline/docker.md" "$(pwd)/docs/reference/commandline/cli.md"
+  fi
 }
 
-buildir=$(mktemp -d -t docker-cli-docsgen.XXXXXXXXXX)
 trap clean EXIT
 
-(
-  set -x
-  cp -r . "$buildir/"
-  cd "$buildir"
-  # init dummy go.mod
-  ./scripts/vendor init
-  # install cli-docs-tool and copy docs/tools.go in root folder
-  # to be able to fetch the required depedencies
-  go mod edit -modfile=vendor.mod -require=github.com/docker/cli-docs-tool@${CLI_DOCS_TOOL_VERSION}
-  cp docs/generate/tools.go .
-  # update vendor
-  ./scripts/vendor update
-  # build docsgen
-  go build -mod=vendor -modfile=vendor.mod -tags docsgen -o /tmp/docsgen ./docs/generate/generate.go
-)
+# build docsgen
+go build -mod=vendor -modfile=vendor.mod -tags docsgen -o /tmp/docsgen ./docs/generate/generate.go
+
+# yaml generation on docs repo needs the cli.md file: https://github.com/docker/cli/pull/3924#discussion_r1059986605
+# but markdown generation docker.md atm. While waiting for a fix in cli-docs-tool
+# we need to first move the cli.md file to docker.md, do the generation and
+# then move it back in trap handler.
+mv "$(pwd)/docs/reference/commandline/cli.md" "$(pwd)/docs/reference/commandline/docker.md"
 
 (
   set -x
diff --git a/scripts/docs/generate-yaml.sh b/scripts/docs/generate-yaml.sh
index 0d67c5e5bb09..7d98e161df5d 100755
--- a/scripts/docs/generate-yaml.sh
+++ b/scripts/docs/generate-yaml.sh
@@ -1,33 +1,20 @@
 #!/usr/bin/env bash
 
-set -eu
-
-: "${CLI_DOCS_TOOL_VERSION=v0.7.0}"
+set -Eeuo pipefail
 
 export GO111MODULE=auto
 
-function clean {
-  rm -rf "$buildir"
+# temporary "go.mod" to make -modfile= work
+touch go.mod
+
+function clean() {
+  rm -f "$(pwd)/go.mod"
 }
 
-buildir=$(mktemp -d -t docker-cli-docsgen.XXXXXXXXXX)
 trap clean EXIT
 
-(
-  set -x
-  cp -r . "$buildir/"
-  cd "$buildir"
-  # init dummy go.mod
-  ./scripts/vendor init
-  # install cli-docs-tool and copy docs/tools.go in root folder
-  # to be able to fetch the required depedencies
-  go mod edit -modfile=vendor.mod -require=github.com/docker/cli-docs-tool@${CLI_DOCS_TOOL_VERSION}
-  cp docs/generate/tools.go .
-  # update vendor
-  ./scripts/vendor update
-  # build docsgen
-  go build -mod=vendor -modfile=vendor.mod -tags docsgen -o /tmp/docsgen ./docs/generate/generate.go
-)
+# build docsgen
+go build -mod=vendor -modfile=vendor.mod -tags docsgen -o /tmp/docsgen ./docs/generate/generate.go
 
 mkdir -p docs/yaml
 set -x
diff --git a/vendor.mod b/vendor.mod
index 4c62fc143db7..c077944c94d3 100644
--- a/vendor.mod
+++ b/vendor.mod
@@ -11,6 +11,7 @@ require (
 	github.com/containerd/containerd v1.7.15
 	github.com/creack/pty v1.1.21
 	github.com/distribution/reference v0.5.0
+	github.com/docker/cli-docs-tool v0.6.0
 	github.com/docker/distribution v2.8.3+incompatible
 	github.com/docker/docker v26.0.1-0.20240422144514-c8af8ebe4a89+incompatible
 	github.com/docker/docker-credential-helpers v0.8.1
@@ -53,6 +54,8 @@ require (
 	tags.cncf.io/container-device-interface v0.6.2
 )
 
+require github.com/cpuguy83/go-md2man/v2 v2.0.3
+
 require (
 	github.com/Azure/go-ansiterm v0.0.0-20210617225240-d185dfc1b5a1 // indirect
 	github.com/Microsoft/go-winio v0.6.1 // indirect
@@ -82,6 +85,7 @@ require (
 	github.com/prometheus/common v0.44.0 // indirect
 	github.com/prometheus/procfs v0.12.0 // indirect
 	github.com/rivo/uniseg v0.2.0 // indirect
+	github.com/russross/blackfriday/v2 v2.1.0 // indirect
 	github.com/xeipuuv/gojsonpointer v0.0.0-20190905194746-02993c407bfb // indirect
 	github.com/xeipuuv/gojsonreference v0.0.0-20180127040603-bd5ef7bd5415 // indirect
 	go.etcd.io/etcd/raft/v3 v3.5.6 // indirect
@@ -97,4 +101,5 @@ require (
 	google.golang.org/genproto/googleapis/rpc v0.0.0-20231016165738-49dd2c1f3d0b // indirect
 	google.golang.org/grpc v1.60.1 // indirect
 	google.golang.org/protobuf v1.33.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
 )
diff --git a/vendor.sum b/vendor.sum
index f89e8e9b45cf..7b2f888a10d6 100644
--- a/vendor.sum
+++ b/vendor.sum
@@ -44,6 +44,7 @@ github.com/containerd/containerd v1.7.15/go.mod h1:ISzRRTMF8EXNpJlTzyr2XMhN+j9K3
 github.com/containerd/log v0.1.0 h1:TCJt7ioM2cr/tfR8GPbGf9/VRAX8D2B4PjzCpfX540I=
 github.com/containerd/log v0.1.0/go.mod h1:VRRf09a7mHDIRezVKTRCrOq78v577GXq3bSa3EhrzVo=
 github.com/coreos/go-systemd/v22 v22.3.2/go.mod h1:Y58oyj3AT4RCenI/lSvhwexgC+NSVTIJ3seZv2GcEnc=
+github.com/cpuguy83/go-md2man/v2 v2.0.3 h1:qMCsGGgs+MAzDFyp9LpAe1Lqy/fY/qCovCm0qnXZOBM=
 github.com/cpuguy83/go-md2man/v2 v2.0.3/go.mod h1:tgQtvFlXSQOSOSIRvRPT7W67SCa46tRHOmNcaadrF8o=
 github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
 github.com/creack/pty v1.1.21 h1:1/QdRyBaHHJP61QkWMXlOIBfsgdDeeKfK8SYVUWJKf0=
@@ -54,6 +55,8 @@ github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSs
 github.com/denisenkom/go-mssqldb v0.0.0-20191128021309-1d7a30a10f73/go.mod h1:xbL0rPBG9cCiLr28tMa8zpbdarY27NDyej4t/EjAShU=
 github.com/distribution/reference v0.5.0 h1:/FUIFXtfc/x2gpa5/VGfiGLuOIdYa1t65IKK2OFGvA0=
 github.com/distribution/reference v0.5.0/go.mod h1:BbU0aIcezP1/5jX/8MP0YiH4SdvB5Y4f/wlDRiLyi3E=
+github.com/docker/cli-docs-tool v0.6.0 h1:Z9x10SaZgFaB6jHgz3OWooynhSa40CsWkpe5hEnG/qA=
+github.com/docker/cli-docs-tool v0.6.0/go.mod h1:zMjqTFCU361PRh8apiXzeAZ1Q/xupbIwTusYpzCXS/o=
 github.com/docker/distribution v2.7.1+incompatible/go.mod h1:J2gT2udsDAN96Uj4KfcMRqY0/ypR+oyYUYmja8H+y+w=
 github.com/docker/distribution v2.8.3+incompatible h1:AtKxIZ36LoNK51+Z6RpzLpddBirtxJnzDrHLEKxTAYk=
 github.com/docker/distribution v2.8.3+incompatible/go.mod h1:J2gT2udsDAN96Uj4KfcMRqY0/ypR+oyYUYmja8H+y+w=
@@ -239,6 +242,7 @@ github.com/rivo/uniseg v0.2.0 h1:S1pD9weZBuJdFmowNwbpi7BJ8TNftyUImj/0WQi72jY=
 github.com/rivo/uniseg v0.2.0/go.mod h1:J6wj4VEh+S6ZtnVlnTBMWIodfgj8LQOQFoIToxlJtxc=
 github.com/rogpeppe/go-internal v1.11.0 h1:cWPaGQEPrBb5/AsnsZesgZZ9yb1OQ+GOISoDNXVBh4M=
 github.com/rogpeppe/go-internal v1.11.0/go.mod h1:ddIwULY96R17DhadqLgMfk9H9tvdUzkipdSkR5nkCZA=
+github.com/russross/blackfriday/v2 v2.1.0 h1:JIOH55/0cWyOuilr9/qlrm0BSXldqnqwMsf35Ld67mk=
 github.com/russross/blackfriday/v2 v2.1.0/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
 github.com/sirupsen/logrus v1.0.6/go.mod h1:pMByvHTf9Beacp5x1UXfOR9xyW/9antXMhjMPG0dEzc=
 github.com/sirupsen/logrus v1.2.0/go.mod h1:LxeOpSwHxABJmUn/MG1IvRgCAasNZTLOkJPxbbu5VWo=
diff --git a/vendor/github.com/cpuguy83/go-md2man/v2/.gitignore b/vendor/github.com/cpuguy83/go-md2man/v2/.gitignore
new file mode 100644
index 000000000000..30f97c3d73ab
--- /dev/null
+++ b/vendor/github.com/cpuguy83/go-md2man/v2/.gitignore
@@ -0,0 +1,2 @@
+go-md2man
+bin
diff --git a/vendor/github.com/cpuguy83/go-md2man/v2/.golangci.yml b/vendor/github.com/cpuguy83/go-md2man/v2/.golangci.yml
new file mode 100644
index 000000000000..71f073f3c6b9
--- /dev/null
+++ b/vendor/github.com/cpuguy83/go-md2man/v2/.golangci.yml
@@ -0,0 +1,6 @@
+# For documentation, see https://golangci-lint.run/usage/configuration/
+
+linters:
+  enable:
+    - gofumpt
+
diff --git a/vendor/github.com/cpuguy83/go-md2man/v2/Dockerfile b/vendor/github.com/cpuguy83/go-md2man/v2/Dockerfile
new file mode 100644
index 000000000000..7181c5306f41
--- /dev/null
+++ b/vendor/github.com/cpuguy83/go-md2man/v2/Dockerfile
@@ -0,0 +1,20 @@
+ARG GO_VERSION=1.18
+ARG GO_IMAGE=golang:${GO_VERSION}
+
+FROM --platform=$BUILDPLATFORM $GO_IMAGE AS build
+COPY . /go/src/github.com/cpuguy83/go-md2man
+WORKDIR /go/src/github.com/cpuguy83/go-md2man
+ARG TARGETOS
+ARG TARGETARCH
+ARG TARGETVARIANT
+RUN \
+    export GOOS="${TARGETOS}"; \
+    export GOARCH="${TARGETARCH}"; \
+    if [ "${TARGETARCH}" = "arm" ] && [ "${TARGETVARIANT}" ]; then \
+    export GOARM="${TARGETVARIANT#v}"; \
+    fi; \
+    CGO_ENABLED=0 go build
+
+FROM scratch
+COPY --from=build /go/src/github.com/cpuguy83/go-md2man/go-md2man /go-md2man
+ENTRYPOINT ["/go-md2man"]
diff --git a/vendor/github.com/cpuguy83/go-md2man/v2/LICENSE.md b/vendor/github.com/cpuguy83/go-md2man/v2/LICENSE.md
new file mode 100644
index 000000000000..1cade6cef6a1
--- /dev/null
+++ b/vendor/github.com/cpuguy83/go-md2man/v2/LICENSE.md
@@ -0,0 +1,21 @@
+The MIT License (MIT)
+
+Copyright (c) 2014 Brian Goff
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/vendor/github.com/cpuguy83/go-md2man/v2/Makefile b/vendor/github.com/cpuguy83/go-md2man/v2/Makefile
new file mode 100644
index 000000000000..437fc9997926
--- /dev/null
+++ b/vendor/github.com/cpuguy83/go-md2man/v2/Makefile
@@ -0,0 +1,35 @@
+GO111MODULE ?= on
+LINTER_BIN ?= golangci-lint
+
+export GO111MODULE
+
+.PHONY:
+build: bin/go-md2man
+
+.PHONY: clean
+clean:
+	@rm -rf bin/*
+
+.PHONY: test
+test:
+	@go test $(TEST_FLAGS) ./...
+
+bin/go-md2man: actual_build_flags := $(BUILD_FLAGS) -o bin/go-md2man
+bin/go-md2man: bin
+	@CGO_ENABLED=0 go build $(actual_build_flags)
+
+bin:
+	@mkdir ./bin
+
+.PHONY: mod
+mod:
+	@go mod tidy
+
+.PHONY: check-mod
+check-mod: # verifies that module changes for go.mod and go.sum are checked in
+	@hack/ci/check_mods.sh
+
+.PHONY: vendor
+vendor: mod
+	@go mod vendor -v
+
diff --git a/vendor/github.com/cpuguy83/go-md2man/v2/README.md b/vendor/github.com/cpuguy83/go-md2man/v2/README.md
new file mode 100644
index 000000000000..0e30d341483c
--- /dev/null
+++ b/vendor/github.com/cpuguy83/go-md2man/v2/README.md
@@ -0,0 +1,15 @@
+go-md2man
+=========
+
+Converts markdown into roff (man pages).
+
+Uses blackfriday to process markdown into man pages.
+
+### Usage
+
+./md2man -in /path/to/markdownfile.md -out /manfile/output/path
+
+### How to contribute
+
+We use go modules to manage dependencies.
+As such you must be using at lest go1.11.
diff --git a/vendor/github.com/cpuguy83/go-md2man/v2/go-md2man.1.md b/vendor/github.com/cpuguy83/go-md2man/v2/go-md2man.1.md
new file mode 100644
index 000000000000..aa4587e279ff
--- /dev/null
+++ b/vendor/github.com/cpuguy83/go-md2man/v2/go-md2man.1.md
@@ -0,0 +1,28 @@
+go-md2man 1 "January 2015" go-md2man "User Manual"
+==================================================
+
+# NAME
+go-md2man - Convert markdown files into manpages
+
+# SYNOPSIS
+**go-md2man** [**-in**=*/path/to/md/file*] [**-out**=*/path/to/output*]
+
+# DESCRIPTION
+**go-md2man** converts standard markdown formatted documents into manpages. It is
+written purely in Go so as to reduce dependencies on 3rd party libs.
+
+By default, the input is stdin and the output is stdout.
+
+# EXAMPLES
+Convert the markdown file *go-md2man.1.md* into a manpage:
+```
+go-md2man < go-md2man.1.md > go-md2man.1
+```
+
+Same, but using command line arguments instead of shell redirection:
+```
+go-md2man -in=go-md2man.1.md -out=go-md2man.1
+```
+
+# HISTORY
+January 2015, Originally compiled by Brian Goff (cpuguy83@gmail.com).
diff --git a/vendor/github.com/cpuguy83/go-md2man/v2/md2man.go b/vendor/github.com/cpuguy83/go-md2man/v2/md2man.go
new file mode 100644
index 000000000000..4ff873b8e767
--- /dev/null
+++ b/vendor/github.com/cpuguy83/go-md2man/v2/md2man.go
@@ -0,0 +1,53 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"io/ioutil"
+	"os"
+
+	"github.com/cpuguy83/go-md2man/v2/md2man"
+)
+
+var (
+	inFilePath  = flag.String("in", "", "Path to file to be processed (default: stdin)")
+	outFilePath = flag.String("out", "", "Path to output processed file (default: stdout)")
+)
+
+func main() {
+	var err error
+	flag.Parse()
+
+	inFile := os.Stdin
+	if *inFilePath != "" {
+		inFile, err = os.Open(*inFilePath)
+		if err != nil {
+			fmt.Println(err)
+			os.Exit(1)
+		}
+	}
+	defer inFile.Close() // nolint: errcheck
+
+	doc, err := ioutil.ReadAll(inFile)
+	if err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
+
+	out := md2man.Render(doc)
+
+	outFile := os.Stdout
+	if *outFilePath != "" {
+		outFile, err = os.Create(*outFilePath)
+		if err != nil {
+			fmt.Println(err)
+			os.Exit(1)
+		}
+		defer outFile.Close() // nolint: errcheck
+	}
+	_, err = outFile.Write(out)
+	if err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
+}
diff --git a/vendor/github.com/cpuguy83/go-md2man/v2/md2man/md2man.go b/vendor/github.com/cpuguy83/go-md2man/v2/md2man/md2man.go
new file mode 100644
index 000000000000..42bf32aab003
--- /dev/null
+++ b/vendor/github.com/cpuguy83/go-md2man/v2/md2man/md2man.go
@@ -0,0 +1,16 @@
+package md2man
+
+import (
+	"github.com/russross/blackfriday/v2"
+)
+
+// Render converts a markdown document into a roff formatted document.
+func Render(doc []byte) []byte {
+	renderer := NewRoffRenderer()
+
+	return blackfriday.Run(doc,
+		[]blackfriday.Option{
+			blackfriday.WithRenderer(renderer),
+			blackfriday.WithExtensions(renderer.GetExtensions()),
+		}...)
+}
diff --git a/vendor/github.com/cpuguy83/go-md2man/v2/md2man/roff.go b/vendor/github.com/cpuguy83/go-md2man/v2/md2man/roff.go
new file mode 100644
index 000000000000..4b19188d90fd
--- /dev/null
+++ b/vendor/github.com/cpuguy83/go-md2man/v2/md2man/roff.go
@@ -0,0 +1,348 @@
+package md2man
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"os"
+	"strings"
+
+	"github.com/russross/blackfriday/v2"
+)
+
+// roffRenderer implements the blackfriday.Renderer interface for creating
+// roff format (manpages) from markdown text
+type roffRenderer struct {
+	extensions   blackfriday.Extensions
+	listCounters []int
+	firstHeader  bool
+	firstDD      bool
+	listDepth    int
+}
+
+const (
+	titleHeader      = ".TH "
+	topLevelHeader   = "\n\n.SH "
+	secondLevelHdr   = "\n.SH "
+	otherHeader      = "\n.SS "
+	crTag            = "\n"
+	emphTag          = "\\fI"
+	emphCloseTag     = "\\fP"
+	strongTag        = "\\fB"
+	strongCloseTag   = "\\fP"
+	breakTag         = "\n.br\n"
+	paraTag          = "\n.PP\n"
+	hruleTag         = "\n.ti 0\n\\l'\\n(.lu'\n"
+	linkTag          = "\n\\[la]"
+	linkCloseTag     = "\\[ra]"
+	codespanTag      = "\\fB"
+	codespanCloseTag = "\\fR"
+	codeTag          = "\n.EX\n"
+	codeCloseTag     = "\n.EE\n"
+	quoteTag         = "\n.PP\n.RS\n"
+	quoteCloseTag    = "\n.RE\n"
+	listTag          = "\n.RS\n"
+	listCloseTag     = "\n.RE\n"
+	dtTag            = "\n.TP\n"
+	dd2Tag           = "\n"
+	tableStart       = "\n.TS\nallbox;\n"
+	tableEnd         = ".TE\n"
+	tableCellStart   = "T{\n"
+	tableCellEnd     = "\nT}\n"
+)
+
+// NewRoffRenderer creates a new blackfriday Renderer for generating roff documents
+// from markdown
+func NewRoffRenderer() *roffRenderer { // nolint: golint
+	var extensions blackfriday.Extensions
+
+	extensions |= blackfriday.NoIntraEmphasis
+	extensions |= blackfriday.Tables
+	extensions |= blackfriday.FencedCode
+	extensions |= blackfriday.SpaceHeadings
+	extensions |= blackfriday.Footnotes
+	extensions |= blackfriday.Titleblock
+	extensions |= blackfriday.DefinitionLists
+	return &roffRenderer{
+		extensions: extensions,
+	}
+}
+
+// GetExtensions returns the list of extensions used by this renderer implementation
+func (r *roffRenderer) GetExtensions() blackfriday.Extensions {
+	return r.extensions
+}
+
+// RenderHeader handles outputting the header at document start
+func (r *roffRenderer) RenderHeader(w io.Writer, ast *blackfriday.Node) {
+	// disable hyphenation
+	out(w, ".nh\n")
+}
+
+// RenderFooter handles outputting the footer at the document end; the roff
+// renderer has no footer information
+func (r *roffRenderer) RenderFooter(w io.Writer, ast *blackfriday.Node) {
+}
+
+// RenderNode is called for each node in a markdown document; based on the node
+// type the equivalent roff output is sent to the writer
+func (r *roffRenderer) RenderNode(w io.Writer, node *blackfriday.Node, entering bool) blackfriday.WalkStatus {
+	walkAction := blackfriday.GoToNext
+
+	switch node.Type {
+	case blackfriday.Text:
+		escapeSpecialChars(w, node.Literal)
+	case blackfriday.Softbreak:
+		out(w, crTag)
+	case blackfriday.Hardbreak:
+		out(w, breakTag)
+	case blackfriday.Emph:
+		if entering {
+			out(w, emphTag)
+		} else {
+			out(w, emphCloseTag)
+		}
+	case blackfriday.Strong:
+		if entering {
+			out(w, strongTag)
+		} else {
+			out(w, strongCloseTag)
+		}
+	case blackfriday.Link:
+		// Don't render the link text for automatic links, because this
+		// will only duplicate the URL in the roff output.
+		// See https://daringfireball.net/projects/markdown/syntax#autolink
+		if !bytes.Equal(node.LinkData.Destination, node.FirstChild.Literal) {
+			out(w, string(node.FirstChild.Literal))
+		}
+		// Hyphens in a link must be escaped to avoid word-wrap in the rendered man page.
+		escapedLink := strings.ReplaceAll(string(node.LinkData.Destination), "-", "\\-")
+		out(w, linkTag+escapedLink+linkCloseTag)
+		walkAction = blackfriday.SkipChildren
+	case blackfriday.Image:
+		// ignore images
+		walkAction = blackfriday.SkipChildren
+	case blackfriday.Code:
+		out(w, codespanTag)
+		escapeSpecialChars(w, node.Literal)
+		out(w, codespanCloseTag)
+	case blackfriday.Document:
+		break
+	case blackfriday.Paragraph:
+		// roff .PP markers break lists
+		if r.listDepth > 0 {
+			return blackfriday.GoToNext
+		}
+		if entering {
+			out(w, paraTag)
+		} else {
+			out(w, crTag)
+		}
+	case blackfriday.BlockQuote:
+		if entering {
+			out(w, quoteTag)
+		} else {
+			out(w, quoteCloseTag)
+		}
+	case blackfriday.Heading:
+		r.handleHeading(w, node, entering)
+	case blackfriday.HorizontalRule:
+		out(w, hruleTag)
+	case blackfriday.List:
+		r.handleList(w, node, entering)
+	case blackfriday.Item:
+		r.handleItem(w, node, entering)
+	case blackfriday.CodeBlock:
+		out(w, codeTag)
+		escapeSpecialChars(w, node.Literal)
+		out(w, codeCloseTag)
+	case blackfriday.Table:
+		r.handleTable(w, node, entering)
+	case blackfriday.TableHead:
+	case blackfriday.TableBody:
+	case blackfriday.TableRow:
+		// no action as cell entries do all the nroff formatting
+		return blackfriday.GoToNext
+	case blackfriday.TableCell:
+		r.handleTableCell(w, node, entering)
+	case blackfriday.HTMLSpan:
+		// ignore other HTML tags
+	case blackfriday.HTMLBlock:
+		if bytes.HasPrefix(node.Literal, []byte("
+
+
+`)
+		if err != nil {
+			return err
+		}
+		if err = icTpl.Execute(&icBuf, struct {
+			Command string
+		}{
+			Command: cmd.CommandPath(),
+		}); err != nil {
+			return err
+		}
+		if err = os.WriteFile(targetPath, icBuf.Bytes(), 0644); err != nil {
+			return err
+		}
+	} else if err := copyFile(sourcePath, targetPath); err != nil {
+		return err
+	}
+
+	content, err := os.ReadFile(targetPath)
+	if err != nil {
+		return err
+	}
+
+	cs := string(content)
+
+	start := strings.Index(cs, "")
+	end := strings.Index(cs, "")
+
+	if start == -1 {
+		return fmt.Errorf("no start marker in %s", mdFile)
+	}
+	if end == -1 {
+		return fmt.Errorf("no end marker in %s", mdFile)
+	}
+
+	out, err := mdCmdOutput(cmd, cs)
+	if err != nil {
+		return err
+	}
+	cont := cs[:start] + "" + "\n" + out + "\n" + cs[end:]
+
+	fi, err := os.Stat(targetPath)
+	if err != nil {
+		return err
+	}
+	if err = os.WriteFile(targetPath, []byte(cont), fi.Mode()); err != nil {
+		return fmt.Errorf("failed to write %s: %w", targetPath, err)
+	}
+
+	return nil
+}
+
+func mdFilename(cmd *cobra.Command) string {
+	name := cmd.CommandPath()
+	if i := strings.Index(name, " "); i >= 0 {
+		name = name[i+1:]
+	}
+	return strings.ReplaceAll(name, " ", "_") + ".md"
+}
+
+func mdMakeLink(txt, link string, f *pflag.Flag, isAnchor bool) string {
+	link = "#" + link
+	annotations, ok := f.Annotations[annotation.ExternalURL]
+	if ok && len(annotations) > 0 {
+		link = annotations[0]
+	} else {
+		if !isAnchor {
+			return txt
+		}
+	}
+
+	return "[" + txt + "](" + link + ")"
+}
+
+type mdTable struct {
+	out       *strings.Builder
+	tabWriter *tabwriter.Writer
+}
+
+func newMdTable(headers ...string) *mdTable {
+	w := &strings.Builder{}
+	t := &mdTable{
+		out: w,
+		// Using tabwriter.Debug, which uses "|" as separator instead of tabs,
+		// which is what we want. It's a bit of a hack, but does the job :)
+		tabWriter: tabwriter.NewWriter(w, 5, 5, 1, ' ', tabwriter.Debug),
+	}
+	t.addHeader(headers...)
+	return t
+}
+
+func (t *mdTable) addHeader(cols ...string) {
+	t.AddRow(cols...)
+	_, _ = t.tabWriter.Write([]byte("|" + strings.Repeat(":---\t", len(cols)) + "\n"))
+}
+
+func (t *mdTable) AddRow(cols ...string) {
+	for i := range cols {
+		cols[i] = mdEscapePipe(cols[i])
+	}
+	_, _ = t.tabWriter.Write([]byte("| " + strings.Join(cols, "\t ") + "\t\n"))
+}
+
+func (t *mdTable) String() string {
+	_ = t.tabWriter.Flush()
+	return adjustSep.ReplaceAllStringFunc(t.out.String()+"\n", func(in string) string {
+		return strings.ReplaceAll(in, " ", "-")
+	})
+}
+
+func mdCmdOutput(cmd *cobra.Command, old string) (string, error) {
+	b := &strings.Builder{}
+
+	desc := cmd.Short
+	if cmd.Long != "" {
+		desc = cmd.Long
+	}
+	if desc != "" {
+		b.WriteString(desc + "\n\n")
+	}
+
+	if aliases := getAliases(cmd); len(aliases) != 0 {
+		b.WriteString("### Aliases\n\n")
+		b.WriteString("`" + strings.Join(aliases, "`, `") + "`")
+		b.WriteString("\n\n")
+	}
+
+	if len(cmd.Commands()) != 0 {
+		b.WriteString("### Subcommands\n\n")
+		table := newMdTable("Name", "Description")
+		for _, c := range cmd.Commands() {
+			if c.Hidden {
+				continue
+			}
+			table.AddRow(fmt.Sprintf("[`%s`](%s)", c.Name(), mdFilename(c)), c.Short)
+		}
+		b.WriteString(table.String() + "\n")
+	}
+
+	// add inherited flags before checking for flags availability
+	cmd.Flags().AddFlagSet(cmd.InheritedFlags())
+
+	if cmd.Flags().HasAvailableFlags() {
+		b.WriteString("### Options\n\n")
+		table := newMdTable("Name", "Type", "Default", "Description")
+		cmd.Flags().VisitAll(func(f *pflag.Flag) {
+			if f.Hidden {
+				return
+			}
+			isLink := strings.Contains(old, "<a name=\""+f.Name+"\"></a>")
+			var name string
+			if f.Shorthand != "" {
+				name = mdMakeLink("`-"+f.Shorthand+"`", f.Name, f, isLink)
+				name += ", "
+			}
+			name += mdMakeLink("`--"+f.Name+"`", f.Name, f, isLink)
+
+			var ftype string
+			if f.Value.Type() != "bool" {
+				ftype = "`" + f.Value.Type() + "`"
+			}
+
+			var defval string
+			if v, ok := f.Annotations[annotation.DefaultValue]; ok && len(v) > 0 {
+				defval = v[0]
+				if cd, ok := f.Annotations[annotation.CodeDelimiter]; ok {
+					defval = strings.ReplaceAll(defval, cd[0], "`")
+				} else if cd, ok := cmd.Annotations[annotation.CodeDelimiter]; ok {
+					defval = strings.ReplaceAll(defval, cd, "`")
+				}
+			} else if f.DefValue != "" && (f.Value.Type() != "bool" && f.DefValue != "true") && f.DefValue != "[]" {
+				defval = "`" + f.DefValue + "`"
+			}
+
+			usage := f.Usage
+			if cd, ok := f.Annotations[annotation.CodeDelimiter]; ok {
+				usage = strings.ReplaceAll(usage, cd[0], "`")
+			} else if cd, ok := cmd.Annotations[annotation.CodeDelimiter]; ok {
+				usage = strings.ReplaceAll(usage, cd, "`")
+			}
+			table.AddRow(name, ftype, defval, mdReplaceNewline(usage))
+		})
+		b.WriteString(table.String())
+	}
+
+	return b.String(), nil
+}
+
+func mdEscapePipe(s string) string {
+	return strings.ReplaceAll(s, `|`, `\|`)
+}
+
+func mdReplaceNewline(s string) string {
+	return nlRegexp.ReplaceAllString(s, "<br>")
+}
diff --git a/vendor/github.com/docker/cli-docs-tool/clidocstool_yaml.go b/vendor/github.com/docker/cli-docs-tool/clidocstool_yaml.go
new file mode 100644
index 000000000000..523524297af4
--- /dev/null
+++ b/vendor/github.com/docker/cli-docs-tool/clidocstool_yaml.go
@@ -0,0 +1,435 @@
+// Copyright 2017 cli-docs-tool authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package clidocstool
+
+import (
+	"fmt"
+	"io"
+	"log"
+	"os"
+	"path/filepath"
+	"sort"
+	"strings"
+
+	"github.com/docker/cli-docs-tool/annotation"
+	"github.com/spf13/cobra"
+	"github.com/spf13/pflag"
+	"gopkg.in/yaml.v3"
+)
+
+type cmdOption struct {
+	Option          string
+	Shorthand       string `yaml:",omitempty"`
+	ValueType       string `yaml:"value_type,omitempty"`
+	DefaultValue    string `yaml:"default_value,omitempty"`
+	Description     string `yaml:",omitempty"`
+	DetailsURL      string `yaml:"details_url,omitempty"` // DetailsURL contains an anchor-id or link for more information on this flag
+	Deprecated      bool
+	Hidden          bool
+	MinAPIVersion   string `yaml:"min_api_version,omitempty"`
+	Experimental    bool
+	ExperimentalCLI bool
+	Kubernetes      bool
+	Swarm           bool
+	OSType          string `yaml:"os_type,omitempty"`
+}
+
+type cmdDoc struct {
+	Name             string      `yaml:"command"`
+	SeeAlso          []string    `yaml:"parent,omitempty"`
+	Version          string      `yaml:"engine_version,omitempty"`
+	Aliases          string      `yaml:",omitempty"`
+	Short            string      `yaml:",omitempty"`
+	Long             string      `yaml:",omitempty"`
+	Usage            string      `yaml:",omitempty"`
+	Pname            string      `yaml:",omitempty"`
+	Plink            string      `yaml:",omitempty"`
+	Cname            []string    `yaml:",omitempty"`
+	Clink            []string    `yaml:",omitempty"`
+	Options          []cmdOption `yaml:",omitempty"`
+	InheritedOptions []cmdOption `yaml:"inherited_options,omitempty"`
+	Example          string      `yaml:"examples,omitempty"`
+	Deprecated       bool
+	Hidden           bool
+	MinAPIVersion    string `yaml:"min_api_version,omitempty"`
+	Experimental     bool
+	ExperimentalCLI  bool
+	Kubernetes       bool
+	Swarm            bool
+	OSType           string `yaml:"os_type,omitempty"`
+}
+
+// GenYamlTree creates yaml structured ref files for this command and all descendants
+// in the directory given. This function may not work
+// correctly if your command names have `-` in them. If you have `cmd` with two
+// subcmds, `sub` and `sub-third`, and `sub` has a subcommand called `third`
+// it is undefined which help output will be in the file `cmd-sub-third.1`.
+func (c *Client) GenYamlTree(cmd *cobra.Command) error {
+	emptyStr := func(s string) string { return "" }
+	if err := c.loadLongDescription(cmd); err != nil {
+		return err
+	}
+	return c.genYamlTreeCustom(cmd, emptyStr)
+}
+
+// genYamlTreeCustom creates yaml structured ref files.
+func (c *Client) genYamlTreeCustom(cmd *cobra.Command, filePrepender func(string) string) error {
+	for _, sc := range cmd.Commands() {
+		if !sc.Runnable() && !sc.HasAvailableSubCommands() {
+			// skip non-runnable commands without subcommands
+			// but *do* generate YAML for hidden and deprecated commands
+			// the YAML will have those included as metadata, so that the
+			// documentation repository can decide whether or not to present them
+			continue
+		}
+		if err := c.genYamlTreeCustom(sc, filePrepender); err != nil {
+			return err
+		}
+	}
+
+	// always disable the addition of [flags] to the usage
+	cmd.DisableFlagsInUseLine = true
+
+	// The "root" command used in the generator is just a "stub", and only has a
+	// list of subcommands, but not (e.g.) global options/flags. We should fix
+	// that, so that the YAML file for the docker "root" command contains the
+	// global flags.
+
+	// Skip the root command altogether, to prevent generating a useless
+	// YAML file for plugins.
+	if c.plugin && !cmd.HasParent() {
+		return nil
+	}
+
+	log.Printf("INFO: Generating YAML for %q", cmd.CommandPath())
+	basename := strings.Replace(cmd.CommandPath(), " ", "_", -1) + ".yaml"
+	target := filepath.Join(c.target, basename)
+	f, err := os.Create(target)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+
+	if _, err := io.WriteString(f, filePrepender(target)); err != nil {
+		return err
+	}
+	return c.genYamlCustom(cmd, f)
+}
+
+// genYamlCustom creates custom yaml output.
+// nolint: gocyclo
+func (c *Client) genYamlCustom(cmd *cobra.Command, w io.Writer) error {
+	const (
+		// shortMaxWidth is the maximum width for the "Short" description before
+		// we force YAML to use multi-line syntax. The goal is to make the total
+		// width fit within 80 characters. This value is based on 80 characters
+		// minus the with of the field, colon, and whitespace ('short: ').
+		shortMaxWidth = 73
+
+		// longMaxWidth is the maximum width for the "Short" description before
+		// we force YAML to use multi-line syntax. The goal is to make the total
+		// width fit within 80 characters. This value is based on 80 characters
+		// minus the with of the field, colon, and whitespace ('long: ').
+		longMaxWidth = 74
+	)
+
+	// necessary to add inherited flags otherwise some
+	// fields are not properly declared like usage
+	cmd.Flags().AddFlagSet(cmd.InheritedFlags())
+
+	cliDoc := cmdDoc{
+		Name:       cmd.CommandPath(),
+		Aliases:    strings.Join(getAliases(cmd), ", "),
+		Short:      forceMultiLine(cmd.Short, shortMaxWidth),
+		Long:       forceMultiLine(cmd.Long, longMaxWidth),
+		Example:    cmd.Example,
+		Deprecated: len(cmd.Deprecated) > 0,
+		Hidden:     cmd.Hidden,
+	}
+
+	if len(cliDoc.Long) == 0 {
+		cliDoc.Long = cliDoc.Short
+	}
+
+	if cmd.Runnable() {
+		cliDoc.Usage = cmd.UseLine()
+	}
+
+	// check recursively to handle inherited annotations
+	for curr := cmd; curr != nil; curr = curr.Parent() {
+		if v, ok := curr.Annotations["version"]; ok && cliDoc.MinAPIVersion == "" {
+			cliDoc.MinAPIVersion = v
+		}
+		if _, ok := curr.Annotations["experimental"]; ok && !cliDoc.Experimental {
+			cliDoc.Experimental = true
+		}
+		if _, ok := curr.Annotations["experimentalCLI"]; ok && !cliDoc.ExperimentalCLI {
+			cliDoc.ExperimentalCLI = true
+		}
+		if _, ok := curr.Annotations["kubernetes"]; ok && !cliDoc.Kubernetes {
+			cliDoc.Kubernetes = true
+		}
+		if _, ok := curr.Annotations["swarm"]; ok && !cliDoc.Swarm {
+			cliDoc.Swarm = true
+		}
+		if o, ok := curr.Annotations["ostype"]; ok && cliDoc.OSType == "" {
+			cliDoc.OSType = o
+		}
+		if _, ok := cmd.Annotations[annotation.CodeDelimiter]; !ok {
+			if cd, cok := curr.Annotations[annotation.CodeDelimiter]; cok {
+				if cmd.Annotations == nil {
+					cmd.Annotations = map[string]string{}
+				}
+				cmd.Annotations[annotation.CodeDelimiter] = cd
+			}
+		}
+	}
+
+	anchors := make(map[string]struct{})
+	if a, ok := cmd.Annotations["anchors"]; ok && a != "" {
+		for _, anchor := range strings.Split(a, ",") {
+			anchors[anchor] = struct{}{}
+		}
+	}
+
+	flags := cmd.NonInheritedFlags()
+	if flags.HasFlags() {
+		cliDoc.Options = genFlagResult(cmd, flags, anchors)
+	}
+	flags = cmd.InheritedFlags()
+	if flags.HasFlags() {
+		cliDoc.InheritedOptions = genFlagResult(cmd, flags, anchors)
+	}
+
+	if hasSeeAlso(cmd) {
+		if cmd.HasParent() {
+			parent := cmd.Parent()
+			cliDoc.Pname = parent.CommandPath()
+			cliDoc.Plink = strings.Replace(cliDoc.Pname, " ", "_", -1) + ".yaml"
+			cmd.VisitParents(func(c *cobra.Command) {
+				if c.DisableAutoGenTag {
+					cmd.DisableAutoGenTag = c.DisableAutoGenTag
+				}
+			})
+		}
+
+		children := cmd.Commands()
+		sort.Sort(byName(children))
+
+		for _, child := range children {
+			if !child.IsAvailableCommand() || child.IsAdditionalHelpTopicCommand() {
+				continue
+			}
+			cliDoc.Cname = append(cliDoc.Cname, cliDoc.Name+" "+child.Name())
+			cliDoc.Clink = append(cliDoc.Clink, strings.Replace(cliDoc.Name+"_"+child.Name(), " ", "_", -1)+".yaml")
+		}
+	}
+
+	final, err := yaml.Marshal(&cliDoc)
+	if err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
+	if _, err := fmt.Fprintln(w, string(final)); err != nil {
+		return err
+	}
+	return nil
+}
+
+func genFlagResult(cmd *cobra.Command, flags *pflag.FlagSet, anchors map[string]struct{}) []cmdOption {
+	var (
+		result []cmdOption
+		opt    cmdOption
+	)
+
+	const (
+		// shortMaxWidth is the maximum width for the "Short" description before
+		// we force YAML to use multi-line syntax. The goal is to make the total
+		// width fit within 80 characters. This value is based on 80 characters
+		// minus the with of the field, colon, and whitespace ('  default_value: ').
+		defaultValueMaxWidth = 64
+
+		// longMaxWidth is the maximum width for the "Short" description before
+		// we force YAML to use multi-line syntax. The goal is to make the total
+		// width fit within 80 characters. This value is based on 80 characters
+		// minus the with of the field, colon, and whitespace ('  description: ').
+		descriptionMaxWidth = 66
+	)
+
+	flags.VisitAll(func(flag *pflag.Flag) {
+		opt = cmdOption{
+			Option:     flag.Name,
+			ValueType:  flag.Value.Type(),
+			Deprecated: len(flag.Deprecated) > 0,
+			Hidden:     flag.Hidden,
+		}
+
+		var defval string
+		if v, ok := flag.Annotations[annotation.DefaultValue]; ok && len(v) > 0 {
+			defval = v[0]
+			if cd, ok := flag.Annotations[annotation.CodeDelimiter]; ok {
+				defval = strings.ReplaceAll(defval, cd[0], "`")
+			} else if cd, ok := cmd.Annotations[annotation.CodeDelimiter]; ok {
+				defval = strings.ReplaceAll(defval, cd, "`")
+			}
+		} else {
+			defval = flag.DefValue
+		}
+		opt.DefaultValue = forceMultiLine(defval, defaultValueMaxWidth)
+
+		usage := flag.Usage
+		if cd, ok := flag.Annotations[annotation.CodeDelimiter]; ok {
+			usage = strings.ReplaceAll(usage, cd[0], "`")
+		} else if cd, ok := cmd.Annotations[annotation.CodeDelimiter]; ok {
+			usage = strings.ReplaceAll(usage, cd, "`")
+		}
+		opt.Description = forceMultiLine(usage, descriptionMaxWidth)
+
+		if v, ok := flag.Annotations[annotation.ExternalURL]; ok && len(v) > 0 {
+			opt.DetailsURL = strings.TrimPrefix(v[0], "https://docs.docker.com")
+		} else if _, ok = anchors[flag.Name]; ok {
+			opt.DetailsURL = "#" + flag.Name
+		}
+
+		// Todo, when we mark a shorthand is deprecated, but specify an empty message.
+		// The flag.ShorthandDeprecated is empty as the shorthand is deprecated.
+		// Using len(flag.ShorthandDeprecated) > 0 can't handle this, others are ok.
+		if !(len(flag.ShorthandDeprecated) > 0) && len(flag.Shorthand) > 0 {
+			opt.Shorthand = flag.Shorthand
+		}
+		if _, ok := flag.Annotations["experimental"]; ok {
+			opt.Experimental = true
+		}
+		if _, ok := flag.Annotations["deprecated"]; ok {
+			opt.Deprecated = true
+		}
+		if v, ok := flag.Annotations["version"]; ok {
+			opt.MinAPIVersion = v[0]
+		}
+		if _, ok := flag.Annotations["experimentalCLI"]; ok {
+			opt.ExperimentalCLI = true
+		}
+		if _, ok := flag.Annotations["kubernetes"]; ok {
+			opt.Kubernetes = true
+		}
+		if _, ok := flag.Annotations["swarm"]; ok {
+			opt.Swarm = true
+		}
+
+		// Note that the annotation can have multiple ostypes set, however, multiple
+		// values are currently not used (and unlikely will).
+		//
+		// To simplify usage of the os_type property in the YAML, and for consistency
+		// with the same property for commands, we're only using the first ostype that's set.
+		if ostypes, ok := flag.Annotations["ostype"]; ok && len(opt.OSType) == 0 && len(ostypes) > 0 {
+			opt.OSType = ostypes[0]
+		}
+
+		result = append(result, opt)
+	})
+
+	return result
+}
+
+// forceMultiLine appends a newline (\n) to strings that are longer than max
+// to force the yaml lib to use block notation (https://yaml.org/spec/1.2/spec.html#Block)
+// instead of a single-line string with newlines and tabs encoded("string\nline1\nline2").
+//
+// This makes the generated YAML more readable, and easier to review changes.
+// max can be used to customize the width to keep the whole line < 80 chars.
+func forceMultiLine(s string, max int) string {
+	s = strings.TrimSpace(s)
+	if len(s) > max && !strings.Contains(s, "\n") {
+		s = s + "\n"
+	}
+	return s
+}
+
+// Small duplication for cobra utils
+func hasSeeAlso(cmd *cobra.Command) bool {
+	if cmd.HasParent() {
+		return true
+	}
+	for _, c := range cmd.Commands() {
+		if !c.IsAvailableCommand() || c.IsAdditionalHelpTopicCommand() {
+			continue
+		}
+		return true
+	}
+	return false
+}
+
+// loadLongDescription gets long descriptions and examples from markdown.
+func (c *Client) loadLongDescription(parentCmd *cobra.Command) error {
+	for _, cmd := range parentCmd.Commands() {
+		if cmd.HasSubCommands() {
+			if err := c.loadLongDescription(cmd); err != nil {
+				return err
+			}
+		}
+		name := cmd.CommandPath()
+		if i := strings.Index(name, " "); i >= 0 {
+			// remove root command / binary name
+			name = name[i+1:]
+		}
+		if name == "" {
+			continue
+		}
+		mdFile := strings.ReplaceAll(name, " ", "_") + ".md"
+		sourcePath := filepath.Join(c.source, mdFile)
+		content, err := os.ReadFile(sourcePath)
+		if os.IsNotExist(err) {
+			log.Printf("WARN: %s does not exist, skipping Markdown examples for YAML doc\n", mdFile)
+			continue
+		}
+		if err != nil {
+			return err
+		}
+		applyDescriptionAndExamples(cmd, string(content))
+	}
+	return nil
+}
+
+// applyDescriptionAndExamples fills in cmd.Long and cmd.Example with the
+// "Description" and "Examples" H2 sections in  mdString (if present).
+func applyDescriptionAndExamples(cmd *cobra.Command, mdString string) {
+	sections := getSections(mdString)
+	var (
+		anchors []string
+		md      string
+	)
+	if sections["description"] != "" {
+		md, anchors = cleanupMarkDown(sections["description"])
+		cmd.Long = md
+		anchors = append(anchors, md)
+	}
+	if sections["examples"] != "" {
+		md, anchors = cleanupMarkDown(sections["examples"])
+		cmd.Example = md
+		anchors = append(anchors, md)
+	}
+	if len(anchors) > 0 {
+		if cmd.Annotations == nil {
+			cmd.Annotations = make(map[string]string)
+		}
+		cmd.Annotations["anchors"] = strings.Join(anchors, ",")
+	}
+}
+
+type byName []*cobra.Command
+
+func (s byName) Len() int           { return len(s) }
+func (s byName) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }
+func (s byName) Less(i, j int) bool { return s[i].Name() < s[j].Name() }
diff --git a/vendor/github.com/docker/cli-docs-tool/docker-bake.hcl b/vendor/github.com/docker/cli-docs-tool/docker-bake.hcl
new file mode 100644
index 000000000000..4a5f44f83018
--- /dev/null
+++ b/vendor/github.com/docker/cli-docs-tool/docker-bake.hcl
@@ -0,0 +1,51 @@
+// Copyright 2021 cli-docs-tool authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+group "default" {
+  targets = ["test"]
+}
+
+group "validate" {
+  targets = ["lint", "vendor-validate", "license-validate"]
+}
+
+target "lint" {
+  target = "lint"
+  output = ["type=cacheonly"]
+}
+
+target "vendor-validate" {
+  target = "vendor-validate"
+  output = ["type=cacheonly"]
+}
+
+target "vendor-update" {
+  target = "vendor-update"
+  output = ["."]
+}
+
+target "test" {
+  target = "test-coverage"
+  output = ["."]
+}
+
+target "license-validate" {
+  target = "license-validate"
+  output = ["type=cacheonly"]
+}
+
+target "license-update" {
+  target = "license-update"
+  output = ["."]
+}
diff --git a/vendor/github.com/docker/cli-docs-tool/markdown.go b/vendor/github.com/docker/cli-docs-tool/markdown.go
new file mode 100644
index 000000000000..32849236ed9c
--- /dev/null
+++ b/vendor/github.com/docker/cli-docs-tool/markdown.go
@@ -0,0 +1,87 @@
+// Copyright 2017 cli-docs-tool authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package clidocstool
+
+import (
+	"regexp"
+	"strings"
+	"unicode"
+)
+
+var (
+	// mdHeading matches MarkDown H1..h6 headings. Note that this regex may produce
+	// false positives for (e.g.) comments in code-blocks (# this is a comment),
+	// so should not be used as a generic regex for other purposes.
+	mdHeading = regexp.MustCompile(`^([#]{1,6})\s(.*)$`)
+	// htmlAnchor matches inline HTML anchors. This is intended to only match anchors
+	// for our use-case; DO NOT consider using this as a generic regex, or at least
+	// not before reading https://stackoverflow.com/a/1732454/1811501.
+	htmlAnchor = regexp.MustCompile(`<a\s+(?:name|id)="?([^"]+)"?\s*></a>\s*`)
+)
+
+// getSections returns all H2 sections by title (lowercase)
+func getSections(mdString string) map[string]string {
+	parsedContent := strings.Split("\n"+mdString, "\n## ")
+	sections := make(map[string]string, len(parsedContent))
+	for _, s := range parsedContent {
+		if strings.HasPrefix(s, "#") {
+			// not a H2 Section
+			continue
+		}
+		parts := strings.SplitN(s, "\n", 2)
+		if len(parts) == 2 {
+			sections[strings.ToLower(parts[0])] = parts[1]
+		}
+	}
+	return sections
+}
+
+// cleanupMarkDown cleans up the MarkDown passed in mdString for inclusion in
+// YAML. It removes trailing whitespace and substitutes tabs for four spaces
+// to prevent YAML switching to use "compact" form; ("line1  \nline\t2\n")
+// which, although equivalent, is hard to read.
+func cleanupMarkDown(mdString string) (md string, anchors []string) {
+	// remove leading/trailing whitespace, and replace tabs in the whole content
+	mdString = strings.TrimSpace(mdString)
+	mdString = strings.ReplaceAll(mdString, "\t", "    ")
+	mdString = strings.ReplaceAll(mdString, "https://docs.docker.com", "")
+
+	var id string
+	// replace trailing whitespace per line, and handle custom anchors
+	lines := strings.Split(mdString, "\n")
+	for i := 0; i < len(lines); i++ {
+		lines[i] = strings.TrimRightFunc(lines[i], unicode.IsSpace)
+		lines[i], id = convertHTMLAnchor(lines[i])
+		if id != "" {
+			anchors = append(anchors, id)
+		}
+	}
+	return strings.Join(lines, "\n"), anchors
+}
+
+// convertHTMLAnchor converts inline anchor-tags in headings (<a name=myanchor></a>)
+// to an extended-markdown property ({#myanchor}). Extended Markdown properties
+// are not supported in GitHub Flavored Markdown, but are supported by Jekyll,
+// and lead to cleaner HTML in our docs, and prevents duplicate anchors.
+// It returns the converted MarkDown heading and the custom ID (if present)
+func convertHTMLAnchor(mdLine string) (md string, customID string) {
+	if m := mdHeading.FindStringSubmatch(mdLine); len(m) > 0 {
+		if a := htmlAnchor.FindStringSubmatch(m[2]); len(a) > 0 {
+			customID = a[1]
+			mdLine = m[1] + " " + htmlAnchor.ReplaceAllString(m[2], "") + " {#" + customID + "}"
+		}
+	}
+	return mdLine, customID
+}
diff --git a/vendor/github.com/russross/blackfriday/v2/.gitignore b/vendor/github.com/russross/blackfriday/v2/.gitignore
new file mode 100644
index 000000000000..75623dcccbb7
--- /dev/null
+++ b/vendor/github.com/russross/blackfriday/v2/.gitignore
@@ -0,0 +1,8 @@
+*.out
+*.swp
+*.8
+*.6
+_obj
+_test*
+markdown
+tags
diff --git a/vendor/github.com/russross/blackfriday/v2/.travis.yml b/vendor/github.com/russross/blackfriday/v2/.travis.yml
new file mode 100644
index 000000000000..b0b525a5a8e1
--- /dev/null
+++ b/vendor/github.com/russross/blackfriday/v2/.travis.yml
@@ -0,0 +1,17 @@
+sudo: false
+language: go
+go:
+  - "1.10.x"
+  - "1.11.x"
+  - tip
+matrix:
+  fast_finish: true
+  allow_failures:
+    - go: tip
+install:
+  - # Do nothing. This is needed to prevent default install action "go get -t -v ./..." from happening here (we want it to happen inside script step).
+script:
+  - go get -t -v ./...
+  - diff -u <(echo -n) <(gofmt -d -s .)
+  - go tool vet .
+  - go test -v ./...
diff --git a/vendor/github.com/russross/blackfriday/v2/LICENSE.txt b/vendor/github.com/russross/blackfriday/v2/LICENSE.txt
new file mode 100644
index 000000000000..2885af3602d8
--- /dev/null
+++ b/vendor/github.com/russross/blackfriday/v2/LICENSE.txt
@@ -0,0 +1,29 @@
+Blackfriday is distributed under the Simplified BSD License:
+
+> Copyright © 2011 Russ Ross
+> All rights reserved.
+>
+> Redistribution and use in source and binary forms, with or without
+> modification, are permitted provided that the following conditions
+> are met:
+>
+> 1.  Redistributions of source code must retain the above copyright
+>     notice, this list of conditions and the following disclaimer.
+>
+> 2.  Redistributions in binary form must reproduce the above
+>     copyright notice, this list of conditions and the following
+>     disclaimer in the documentation and/or other materials provided with
+>     the distribution.
+>
+> THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+> "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+> LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+> FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+> COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+> INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+> BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+> LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+> CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+> LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+> ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+> POSSIBILITY OF SUCH DAMAGE.
diff --git a/vendor/github.com/russross/blackfriday/v2/README.md b/vendor/github.com/russross/blackfriday/v2/README.md
new file mode 100644
index 000000000000..d9c08a22fc54
--- /dev/null
+++ b/vendor/github.com/russross/blackfriday/v2/README.md
@@ -0,0 +1,335 @@
+Blackfriday
+[![Build Status][BuildV2SVG]][BuildV2URL]
+[![PkgGoDev][PkgGoDevV2SVG]][PkgGoDevV2URL]
+===========
+
+Blackfriday is a [Markdown][1] processor implemented in [Go][2]. It
+is paranoid about its input (so you can safely feed it user-supplied
+data), it is fast, it supports common extensions (tables, smart
+punctuation substitutions, etc.), and it is safe for all utf-8
+(unicode) input.
+
+HTML output is currently supported, along with Smartypants
+extensions.
+
+It started as a translation from C of [Sundown][3].
+
+
+Installation
+------------
+
+Blackfriday is compatible with modern Go releases in module mode.
+With Go installed:
+
+    go get github.com/russross/blackfriday/v2
+
+will resolve and add the package to the current development module,
+then build and install it. Alternatively, you can achieve the same
+if you import it in a package:
+
+    import "github.com/russross/blackfriday/v2"
+
+and `go get` without parameters.
+
+Legacy GOPATH mode is unsupported.
+
+
+Versions
+--------
+
+Currently maintained and recommended version of Blackfriday is `v2`. It's being
+developed on its own branch: https://github.com/russross/blackfriday/tree/v2 and the
+documentation is available at
+https://pkg.go.dev/github.com/russross/blackfriday/v2.
+
+It is `go get`-able in module mode at `github.com/russross/blackfriday/v2`.
+
+Version 2 offers a number of improvements over v1:
+
+* Cleaned up API
+* A separate call to [`Parse`][4], which produces an abstract syntax tree for
+  the document
+* Latest bug fixes
+* Flexibility to easily add your own rendering extensions
+
+Potential drawbacks:
+
+* Our benchmarks show v2 to be slightly slower than v1. Currently in the
+  ballpark of around 15%.
+* API breakage. If you can't afford modifying your code to adhere to the new API
+  and don't care too much about the new features, v2 is probably not for you.
+* Several bug fixes are trailing behind and still need to be forward-ported to
+  v2. See issue [#348](https://github.com/russross/blackfriday/issues/348) for
+  tracking.
+
+If you are still interested in the legacy `v1`, you can import it from
+`github.com/russross/blackfriday`. Documentation for the legacy v1 can be found
+here: https://pkg.go.dev/github.com/russross/blackfriday.
+
+
+Usage
+-----
+
+For the most sensible markdown processing, it is as simple as getting your input
+into a byte slice and calling:
+
+```go
+output := blackfriday.Run(input)
+```
+
+Your input will be parsed and the output rendered with a set of most popular
+extensions enabled. If you want the most basic feature set, corresponding with
+the bare Markdown specification, use:
+
+```go
+output := blackfriday.Run(input, blackfriday.WithNoExtensions())
+```
+
+### Sanitize untrusted content
+
+Blackfriday itself does nothing to protect against malicious content. If you are
+dealing with user-supplied markdown, we recommend running Blackfriday's output
+through HTML sanitizer such as [Bluemonday][5].
+
+Here's an example of simple usage of Blackfriday together with Bluemonday:
+
+```go
+import (
+    "github.com/microcosm-cc/bluemonday"
+    "github.com/russross/blackfriday/v2"
+)
+
+// ...
+unsafe := blackfriday.Run(input)
+html := bluemonday.UGCPolicy().SanitizeBytes(unsafe)
+```
+
+### Custom options
+
+If you want to customize the set of options, use `blackfriday.WithExtensions`,
+`blackfriday.WithRenderer` and `blackfriday.WithRefOverride`.
+
+### `blackfriday-tool`
+
+You can also check out `blackfriday-tool` for a more complete example
+of how to use it. Download and install it using:
+
+    go get github.com/russross/blackfriday-tool
+
+This is a simple command-line tool that allows you to process a
+markdown file using a standalone program.  You can also browse the
+source directly on github if you are just looking for some example
+code:
+
+* <https://github.com/russross/blackfriday-tool>
+
+Note that if you have not already done so, installing
+`blackfriday-tool` will be sufficient to download and install
+blackfriday in addition to the tool itself. The tool binary will be
+installed in `$GOPATH/bin`.  This is a statically-linked binary that
+can be copied to wherever you need it without worrying about
+dependencies and library versions.
+
+### Sanitized anchor names
+
+Blackfriday includes an algorithm for creating sanitized anchor names
+corresponding to a given input text. This algorithm is used to create
+anchors for headings when `AutoHeadingIDs` extension is enabled. The
+algorithm has a specification, so that other packages can create
+compatible anchor names and links to those anchors.
+
+The specification is located at https://pkg.go.dev/github.com/russross/blackfriday/v2#hdr-Sanitized_Anchor_Names.
+
+[`SanitizedAnchorName`](https://pkg.go.dev/github.com/russross/blackfriday/v2#SanitizedAnchorName) exposes this functionality, and can be used to
+create compatible links to the anchor names generated by blackfriday.
+This algorithm is also implemented in a small standalone package at
+[`github.com/shurcooL/sanitized_anchor_name`](https://pkg.go.dev/github.com/shurcooL/sanitized_anchor_name). It can be useful for clients
+that want a small package and don't need full functionality of blackfriday.
+
+
+Features
+--------
+
+All features of Sundown are supported, including:
+
+*   **Compatibility**. The Markdown v1.0.3 test suite passes with
+    the `--tidy` option.  Without `--tidy`, the differences are
+    mostly in whitespace and entity escaping, where blackfriday is
+    more consistent and cleaner.
+
+*   **Common extensions**, including table support, fenced code
+    blocks, autolinks, strikethroughs, non-strict emphasis, etc.
+
+*   **Safety**. Blackfriday is paranoid when parsing, making it safe
+    to feed untrusted user input without fear of bad things
+    happening. The test suite stress tests this and there are no
+    known inputs that make it crash.  If you find one, please let me
+    know and send me the input that does it.
+
+    NOTE: "safety" in this context means *runtime safety only*. In order to
+    protect yourself against JavaScript injection in untrusted content, see
+    [this example](https://github.com/russross/blackfriday#sanitize-untrusted-content).
+
+*   **Fast processing**. It is fast enough to render on-demand in
+    most web applications without having to cache the output.
+
+*   **Thread safety**. You can run multiple parsers in different
+    goroutines without ill effect. There is no dependence on global
+    shared state.
+
+*   **Minimal dependencies**. Blackfriday only depends on standard
+    library packages in Go. The source code is pretty
+    self-contained, so it is easy to add to any project, including
+    Google App Engine projects.
+
+*   **Standards compliant**. Output successfully validates using the
+    W3C validation tool for HTML 4.01 and XHTML 1.0 Transitional.
+
+
+Extensions
+----------
+
+In addition to the standard markdown syntax, this package
+implements the following extensions:
+
+*   **Intra-word emphasis supression**. The `_` character is
+    commonly used inside words when discussing code, so having
+    markdown interpret it as an emphasis command is usually the
+    wrong thing. Blackfriday lets you treat all emphasis markers as
+    normal characters when they occur inside a word.
+
+*   **Tables**. Tables can be created by drawing them in the input
+    using a simple syntax:
+
+    ```
+    Name    | Age
+    --------|------
+    Bob     | 27
+    Alice   | 23
+    ```
+
+*   **Fenced code blocks**. In addition to the normal 4-space
+    indentation to mark code blocks, you can explicitly mark them
+    and supply a language (to make syntax highlighting simple). Just
+    mark it like this:
+
+        ```go
+        func getTrue() bool {
+            return true
+        }
+        ```
+
+    You can use 3 or more backticks to mark the beginning of the
+    block, and the same number to mark the end of the block.
+
+    To preserve classes of fenced code blocks while using the bluemonday
+    HTML sanitizer, use the following policy:
+
+    ```go
+    p := bluemonday.UGCPolicy()
+    p.AllowAttrs("class").Matching(regexp.MustCompile("^language-[a-zA-Z0-9]+$")).OnElements("code")
+    html := p.SanitizeBytes(unsafe)
+    ```
+
+*   **Definition lists**. A simple definition list is made of a single-line
+    term followed by a colon and the definition for that term.
+
+        Cat
+        : Fluffy animal everyone likes
+
+        Internet
+        : Vector of transmission for pictures of cats
+
+    Terms must be separated from the previous definition by a blank line.
+
+*   **Footnotes**. A marker in the text that will become a superscript number;
+    a footnote definition that will be placed in a list of footnotes at the
+    end of the document. A footnote looks like this:
+
+        This is a footnote.[^1]
+
+        [^1]: the footnote text.
+
+*   **Autolinking**. Blackfriday can find URLs that have not been
+    explicitly marked as links and turn them into links.
+
+*   **Strikethrough**. Use two tildes (`~~`) to mark text that
+    should be crossed out.
+
+*   **Hard line breaks**. With this extension enabled newlines in the input
+    translate into line breaks in the output. This extension is off by default.
+
+*   **Smart quotes**. Smartypants-style punctuation substitution is
+    supported, turning normal double- and single-quote marks into
+    curly quotes, etc.
+
+*   **LaTeX-style dash parsing** is an additional option, where `--`
+    is translated into `&ndash;`, and `---` is translated into
+    `&mdash;`. This differs from most smartypants processors, which
+    turn a single hyphen into an ndash and a double hyphen into an
+    mdash.
+
+*   **Smart fractions**, where anything that looks like a fraction
+    is translated into suitable HTML (instead of just a few special
+    cases like most smartypant processors). For example, `4/5`
+    becomes `<sup>4</sup>&frasl;<sub>5</sub>`, which renders as
+    <sup>4</sup>&frasl;<sub>5</sub>.
+
+
+Other renderers
+---------------
+
+Blackfriday is structured to allow alternative rendering engines. Here
+are a few of note:
+
+*   [github_flavored_markdown](https://pkg.go.dev/github.com/shurcooL/github_flavored_markdown):
+    provides a GitHub Flavored Markdown renderer with fenced code block
+    highlighting, clickable heading anchor links.
+
+    It's not customizable, and its goal is to produce HTML output
+    equivalent to the [GitHub Markdown API endpoint](https://developer.github.com/v3/markdown/#render-a-markdown-document-in-raw-mode),
+    except the rendering is performed locally.
+
+*   [markdownfmt](https://github.com/shurcooL/markdownfmt): like gofmt,
+    but for markdown.
+
+*   [LaTeX output](https://gitlab.com/ambrevar/blackfriday-latex):
+    renders output as LaTeX.
+
+*   [bfchroma](https://github.com/Depado/bfchroma/): provides convenience
+    integration with the [Chroma](https://github.com/alecthomas/chroma) code
+    highlighting library. bfchroma is only compatible with v2 of Blackfriday and
+    provides a drop-in renderer ready to use with Blackfriday, as well as
+    options and means for further customization.
+
+*   [Blackfriday-Confluence](https://github.com/kentaro-m/blackfriday-confluence): provides a [Confluence Wiki Markup](https://confluence.atlassian.com/doc/confluence-wiki-markup-251003035.html) renderer.
+
+*   [Blackfriday-Slack](https://github.com/karriereat/blackfriday-slack): converts markdown to slack message style
+
+
+TODO
+----
+
+*   More unit testing
+*   Improve Unicode support. It does not understand all Unicode
+    rules (about what constitutes a letter, a punctuation symbol,
+    etc.), so it may fail to detect word boundaries correctly in
+    some instances. It is safe on all UTF-8 input.
+
+
+License
+-------
+
+[Blackfriday is distributed under the Simplified BSD License](LICENSE.txt)
+
+
+   [1]: https://daringfireball.net/projects/markdown/ "Markdown"
+   [2]: https://golang.org/ "Go Language"
+   [3]: https://github.com/vmg/sundown "Sundown"
+   [4]: https://pkg.go.dev/github.com/russross/blackfriday/v2#Parse "Parse func"
+   [5]: https://github.com/microcosm-cc/bluemonday "Bluemonday"
+
+   [BuildV2SVG]: https://travis-ci.org/russross/blackfriday.svg?branch=v2
+   [BuildV2URL]: https://travis-ci.org/russross/blackfriday
+   [PkgGoDevV2SVG]: https://pkg.go.dev/badge/github.com/russross/blackfriday/v2
+   [PkgGoDevV2URL]: https://pkg.go.dev/github.com/russross/blackfriday/v2
diff --git a/vendor/github.com/russross/blackfriday/v2/block.go b/vendor/github.com/russross/blackfriday/v2/block.go
new file mode 100644
index 000000000000..dcd61e6e35bc
--- /dev/null
+++ b/vendor/github.com/russross/blackfriday/v2/block.go
@@ -0,0 +1,1612 @@
+//
+// Blackfriday Markdown Processor
+// Available at http://github.com/russross/blackfriday
+//
+// Copyright © 2011 Russ Ross <russ@russross.com>.
+// Distributed under the Simplified BSD License.
+// See README.md for details.
+//
+
+//
+// Functions to parse block-level elements.
+//
+
+package blackfriday
+
+import (
+	"bytes"
+	"html"
+	"regexp"
+	"strings"
+	"unicode"
+)
+
+const (
+	charEntity = "&(?:#x[a-f0-9]{1,8}|#[0-9]{1,8}|[a-z][a-z0-9]{1,31});"
+	escapable  = "[!\"#$%&'()*+,./:;<=>?@[\\\\\\]^_`{|}~-]"
+)
+
+var (
+	reBackslashOrAmp      = regexp.MustCompile("[\\&]")
+	reEntityOrEscapedChar = regexp.MustCompile("(?i)\\\\" + escapable + "|" + charEntity)
+)
+
+// Parse block-level data.
+// Note: this function and many that it calls assume that
+// the input buffer ends with a newline.
+func (p *Markdown) block(data []byte) {
+	// this is called recursively: enforce a maximum depth
+	if p.nesting >= p.maxNesting {
+		return
+	}
+	p.nesting++
+
+	// parse out one block-level construct at a time
+	for len(data) > 0 {
+		// prefixed heading:
+		//
+		// # Heading 1
+		// ## Heading 2
+		// ...
+		// ###### Heading 6
+		if p.isPrefixHeading(data) {
+			data = data[p.prefixHeading(data):]
+			continue
+		}
+
+		// block of preformatted HTML:
+		//
+		// <div>
+		//     ...
+		// </div>
+		if data[0] == '<' {
+			if i := p.html(data, true); i > 0 {
+				data = data[i:]
+				continue
+			}
+		}
+
+		// title block
+		//
+		// % stuff
+		// % more stuff
+		// % even more stuff
+		if p.extensions&Titleblock != 0 {
+			if data[0] == '%' {
+				if i := p.titleBlock(data, true); i > 0 {
+					data = data[i:]
+					continue
+				}
+			}
+		}
+
+		// blank lines.  note: returns the # of bytes to skip
+		if i := p.isEmpty(data); i > 0 {
+			data = data[i:]
+			continue
+		}
+
+		// indented code block:
+		//
+		//     func max(a, b int) int {
+		//         if a > b {
+		//             return a
+		//         }
+		//         return b
+		//      }
+		if p.codePrefix(data) > 0 {
+			data = data[p.code(data):]
+			continue
+		}
+
+		// fenced code block:
+		//
+		// ``` go
+		// func fact(n int) int {
+		//     if n <= 1 {
+		//         return n
+		//     }
+		//     return n * fact(n-1)
+		// }
+		// ```
+		if p.extensions&FencedCode != 0 {
+			if i := p.fencedCodeBlock(data, true); i > 0 {
+				data = data[i:]
+				continue
+			}
+		}
+
+		// horizontal rule:
+		//
+		// ------
+		// or
+		// ******
+		// or
+		// ______
+		if p.isHRule(data) {
+			p.addBlock(HorizontalRule, nil)
+			var i int
+			for i = 0; i < len(data) && data[i] != '\n'; i++ {
+			}
+			data = data[i:]
+			continue
+		}
+
+		// block quote:
+		//
+		// > A big quote I found somewhere
+		// > on the web
+		if p.quotePrefix(data) > 0 {
+			data = data[p.quote(data):]
+			continue
+		}
+
+		// table:
+		//
+		// Name  | Age | Phone
+		// ------|-----|---------
+		// Bob   | 31  | 555-1234
+		// Alice | 27  | 555-4321
+		if p.extensions&Tables != 0 {
+			if i := p.table(data); i > 0 {
+				data = data[i:]
+				continue
+			}
+		}
+
+		// an itemized/unordered list:
+		//
+		// * Item 1
+		// * Item 2
+		//
+		// also works with + or -
+		if p.uliPrefix(data) > 0 {
+			data = data[p.list(data, 0):]
+			continue
+		}
+
+		// a numbered/ordered list:
+		//
+		// 1. Item 1
+		// 2. Item 2
+		if p.oliPrefix(data) > 0 {
+			data = data[p.list(data, ListTypeOrdered):]
+			continue
+		}
+
+		// definition lists:
+		//
+		// Term 1
+		// :   Definition a
+		// :   Definition b
+		//
+		// Term 2
+		// :   Definition c
+		if p.extensions&DefinitionLists != 0 {
+			if p.dliPrefix(data) > 0 {
+				data = data[p.list(data, ListTypeDefinition):]
+				continue
+			}
+		}
+
+		// anything else must look like a normal paragraph
+		// note: this finds underlined headings, too
+		data = data[p.paragraph(data):]
+	}
+
+	p.nesting--
+}
+
+func (p *Markdown) addBlock(typ NodeType, content []byte) *Node {
+	p.closeUnmatchedBlocks()
+	container := p.addChild(typ, 0)
+	container.content = content
+	return container
+}
+
+func (p *Markdown) isPrefixHeading(data []byte) bool {
+	if data[0] != '#' {
+		return false
+	}
+
+	if p.extensions&SpaceHeadings != 0 {
+		level := 0
+		for level < 6 && level < len(data) && data[level] == '#' {
+			level++
+		}
+		if level == len(data) || data[level] != ' ' {
+			return false
+		}
+	}
+	return true
+}
+
+func (p *Markdown) prefixHeading(data []byte) int {
+	level := 0
+	for level < 6 && level < len(data) && data[level] == '#' {
+		level++
+	}
+	i := skipChar(data, level, ' ')
+	end := skipUntilChar(data, i, '\n')
+	skip := end
+	id := ""
+	if p.extensions&HeadingIDs != 0 {
+		j, k := 0, 0
+		// find start/end of heading id
+		for j = i; j < end-1 && (data[j] != '{' || data[j+1] != '#'); j++ {
+		}
+		for k = j + 1; k < end && data[k] != '}'; k++ {
+		}
+		// extract heading id iff found
+		if j < end && k < end {
+			id = string(data[j+2 : k])
+			end = j
+			skip = k + 1
+			for end > 0 && data[end-1] == ' ' {
+				end--
+			}
+		}
+	}
+	for end > 0 && data[end-1] == '#' {
+		if isBackslashEscaped(data, end-1) {
+			break
+		}
+		end--
+	}
+	for end > 0 && data[end-1] == ' ' {
+		end--
+	}
+	if end > i {
+		if id == "" && p.extensions&AutoHeadingIDs != 0 {
+			id = SanitizedAnchorName(string(data[i:end]))
+		}
+		block := p.addBlock(Heading, data[i:end])
+		block.HeadingID = id
+		block.Level = level
+	}
+	return skip
+}
+
+func (p *Markdown) isUnderlinedHeading(data []byte) int {
+	// test of level 1 heading
+	if data[0] == '=' {
+		i := skipChar(data, 1, '=')
+		i = skipChar(data, i, ' ')
+		if i < len(data) && data[i] == '\n' {
+			return 1
+		}
+		return 0
+	}
+
+	// test of level 2 heading
+	if data[0] == '-' {
+		i := skipChar(data, 1, '-')
+		i = skipChar(data, i, ' ')
+		if i < len(data) && data[i] == '\n' {
+			return 2
+		}
+		return 0
+	}
+
+	return 0
+}
+
+func (p *Markdown) titleBlock(data []byte, doRender bool) int {
+	if data[0] != '%' {
+		return 0
+	}
+	splitData := bytes.Split(data, []byte("\n"))
+	var i int
+	for idx, b := range splitData {
+		if !bytes.HasPrefix(b, []byte("%")) {
+			i = idx // - 1
+			break
+		}
+	}
+
+	data = bytes.Join(splitData[0:i], []byte("\n"))
+	consumed := len(data)
+	data = bytes.TrimPrefix(data, []byte("% "))
+	data = bytes.Replace(data, []byte("\n% "), []byte("\n"), -1)
+	block := p.addBlock(Heading, data)
+	block.Level = 1
+	block.IsTitleblock = true
+
+	return consumed
+}
+
+func (p *Markdown) html(data []byte, doRender bool) int {
+	var i, j int
+
+	// identify the opening tag
+	if data[0] != '<' {
+		return 0
+	}
+	curtag, tagfound := p.htmlFindTag(data[1:])
+
+	// handle special cases
+	if !tagfound {
+		// check for an HTML comment
+		if size := p.htmlComment(data, doRender); size > 0 {
+			return size
+		}
+
+		// check for an <hr> tag
+		if size := p.htmlHr(data, doRender); size > 0 {
+			return size
+		}
+
+		// no special case recognized
+		return 0
+	}
+
+	// look for an unindented matching closing tag
+	// followed by a blank line
+	found := false
+	/*
+		closetag := []byte("\n</" + curtag + ">")
+		j = len(curtag) + 1
+		for !found {
+			// scan for a closing tag at the beginning of a line
+			if skip := bytes.Index(data[j:], closetag); skip >= 0 {
+				j += skip + len(closetag)
+			} else {
+				break
+			}
+
+			// see if it is the only thing on the line
+			if skip := p.isEmpty(data[j:]); skip > 0 {
+				// see if it is followed by a blank line/eof
+				j += skip
+				if j >= len(data) {
+					found = true
+					i = j
+				} else {
+					if skip := p.isEmpty(data[j:]); skip > 0 {
+						j += skip
+						found = true
+						i = j
+					}
+				}
+			}
+		}
+	*/
+
+	// if not found, try a second pass looking for indented match
+	// but not if tag is "ins" or "del" (following original Markdown.pl)
+	if !found && curtag != "ins" && curtag != "del" {
+		i = 1
+		for i < len(data) {
+			i++
+			for i < len(data) && !(data[i-1] == '<' && data[i] == '/') {
+				i++
+			}
+
+			if i+2+len(curtag) >= len(data) {
+				break
+			}
+
+			j = p.htmlFindEnd(curtag, data[i-1:])
+
+			if j > 0 {
+				i += j - 1
+				found = true
+				break
+			}
+		}
+	}
+
+	if !found {
+		return 0
+	}
+
+	// the end of the block has been found
+	if doRender {
+		// trim newlines
+		end := i
+		for end > 0 && data[end-1] == '\n' {
+			end--
+		}
+		finalizeHTMLBlock(p.addBlock(HTMLBlock, data[:end]))
+	}
+
+	return i
+}
+
+func finalizeHTMLBlock(block *Node) {
+	block.Literal = block.content
+	block.content = nil
+}
+
+// HTML comment, lax form
+func (p *Markdown) htmlComment(data []byte, doRender bool) int {
+	i := p.inlineHTMLComment(data)
+	// needs to end with a blank line
+	if j := p.isEmpty(data[i:]); j > 0 {
+		size := i + j
+		if doRender {
+			// trim trailing newlines
+			end := size
+			for end > 0 && data[end-1] == '\n' {
+				end--
+			}
+			block := p.addBlock(HTMLBlock, data[:end])
+			finalizeHTMLBlock(block)
+		}
+		return size
+	}
+	return 0
+}
+
+// HR, which is the only self-closing block tag considered
+func (p *Markdown) htmlHr(data []byte, doRender bool) int {
+	if len(data) < 4 {
+		return 0
+	}
+	if data[0] != '<' || (data[1] != 'h' && data[1] != 'H') || (data[2] != 'r' && data[2] != 'R') {
+		return 0
+	}
+	if data[3] != ' ' && data[3] != '/' && data[3] != '>' {
+		// not an <hr> tag after all; at least not a valid one
+		return 0
+	}
+	i := 3
+	for i < len(data) && data[i] != '>' && data[i] != '\n' {
+		i++
+	}
+	if i < len(data) && data[i] == '>' {
+		i++
+		if j := p.isEmpty(data[i:]); j > 0 {
+			size := i + j
+			if doRender {
+				// trim newlines
+				end := size
+				for end > 0 && data[end-1] == '\n' {
+					end--
+				}
+				finalizeHTMLBlock(p.addBlock(HTMLBlock, data[:end]))
+			}
+			return size
+		}
+	}
+	return 0
+}
+
+func (p *Markdown) htmlFindTag(data []byte) (string, bool) {
+	i := 0
+	for i < len(data) && isalnum(data[i]) {
+		i++
+	}
+	key := string(data[:i])
+	if _, ok := blockTags[key]; ok {
+		return key, true
+	}
+	return "", false
+}
+
+func (p *Markdown) htmlFindEnd(tag string, data []byte) int {
+	// assume data[0] == '<' && data[1] == '/' already tested
+	if tag == "hr" {
+		return 2
+	}
+	// check if tag is a match
+	closetag := []byte("</" + tag + ">")
+	if !bytes.HasPrefix(data, closetag) {
+		return 0
+	}
+	i := len(closetag)
+
+	// check that the rest of the line is blank
+	skip := 0
+	if skip = p.isEmpty(data[i:]); skip == 0 {
+		return 0
+	}
+	i += skip
+	skip = 0
+
+	if i >= len(data) {
+		return i
+	}
+
+	if p.extensions&LaxHTMLBlocks != 0 {
+		return i
+	}
+	if skip = p.isEmpty(data[i:]); skip == 0 {
+		// following line must be blank
+		return 0
+	}
+
+	return i + skip
+}
+
+func (*Markdown) isEmpty(data []byte) int {
+	// it is okay to call isEmpty on an empty buffer
+	if len(data) == 0 {
+		return 0
+	}
+
+	var i int
+	for i = 0; i < len(data) && data[i] != '\n'; i++ {
+		if data[i] != ' ' && data[i] != '\t' {
+			return 0
+		}
+	}
+	if i < len(data) && data[i] == '\n' {
+		i++
+	}
+	return i
+}
+
+func (*Markdown) isHRule(data []byte) bool {
+	i := 0
+
+	// skip up to three spaces
+	for i < 3 && data[i] == ' ' {
+		i++
+	}
+
+	// look at the hrule char
+	if data[i] != '*' && data[i] != '-' && data[i] != '_' {
+		return false
+	}
+	c := data[i]
+
+	// the whole line must be the char or whitespace
+	n := 0
+	for i < len(data) && data[i] != '\n' {
+		switch {
+		case data[i] == c:
+			n++
+		case data[i] != ' ':
+			return false
+		}
+		i++
+	}
+
+	return n >= 3
+}
+
+// isFenceLine checks if there's a fence line (e.g., ``` or ``` go) at the beginning of data,
+// and returns the end index if so, or 0 otherwise. It also returns the marker found.
+// If info is not nil, it gets set to the syntax specified in the fence line.
+func isFenceLine(data []byte, info *string, oldmarker string) (end int, marker string) {
+	i, size := 0, 0
+
+	// skip up to three spaces
+	for i < len(data) && i < 3 && data[i] == ' ' {
+		i++
+	}
+
+	// check for the marker characters: ~ or `
+	if i >= len(data) {
+		return 0, ""
+	}
+	if data[i] != '~' && data[i] != '`' {
+		return 0, ""
+	}
+
+	c := data[i]
+
+	// the whole line must be the same char or whitespace
+	for i < len(data) && data[i] == c {
+		size++
+		i++
+	}
+
+	// the marker char must occur at least 3 times
+	if size < 3 {
+		return 0, ""
+	}
+	marker = string(data[i-size : i])
+
+	// if this is the end marker, it must match the beginning marker
+	if oldmarker != "" && marker != oldmarker {
+		return 0, ""
+	}
+
+	// TODO(shurcooL): It's probably a good idea to simplify the 2 code paths here
+	// into one, always get the info string, and discard it if the caller doesn't care.
+	if info != nil {
+		infoLength := 0
+		i = skipChar(data, i, ' ')
+
+		if i >= len(data) {
+			if i == len(data) {
+				return i, marker
+			}
+			return 0, ""
+		}
+
+		infoStart := i
+
+		if data[i] == '{' {
+			i++
+			infoStart++
+
+			for i < len(data) && data[i] != '}' && data[i] != '\n' {
+				infoLength++
+				i++
+			}
+
+			if i >= len(data) || data[i] != '}' {
+				return 0, ""
+			}
+
+			// strip all whitespace at the beginning and the end
+			// of the {} block
+			for infoLength > 0 && isspace(data[infoStart]) {
+				infoStart++
+				infoLength--
+			}
+
+			for infoLength > 0 && isspace(data[infoStart+infoLength-1]) {
+				infoLength--
+			}
+			i++
+			i = skipChar(data, i, ' ')
+		} else {
+			for i < len(data) && !isverticalspace(data[i]) {
+				infoLength++
+				i++
+			}
+		}
+
+		*info = strings.TrimSpace(string(data[infoStart : infoStart+infoLength]))
+	}
+
+	if i == len(data) {
+		return i, marker
+	}
+	if i > len(data) || data[i] != '\n' {
+		return 0, ""
+	}
+	return i + 1, marker // Take newline into account.
+}
+
+// fencedCodeBlock returns the end index if data contains a fenced code block at the beginning,
+// or 0 otherwise. It writes to out if doRender is true, otherwise it has no side effects.
+// If doRender is true, a final newline is mandatory to recognize the fenced code block.
+func (p *Markdown) fencedCodeBlock(data []byte, doRender bool) int {
+	var info string
+	beg, marker := isFenceLine(data, &info, "")
+	if beg == 0 || beg >= len(data) {
+		return 0
+	}
+	fenceLength := beg - 1
+
+	var work bytes.Buffer
+	work.Write([]byte(info))
+	work.WriteByte('\n')
+
+	for {
+		// safe to assume beg < len(data)
+
+		// check for the end of the code block
+		fenceEnd, _ := isFenceLine(data[beg:], nil, marker)
+		if fenceEnd != 0 {
+			beg += fenceEnd
+			break
+		}
+
+		// copy the current line
+		end := skipUntilChar(data, beg, '\n') + 1
+
+		// did we reach the end of the buffer without a closing marker?
+		if end >= len(data) {
+			return 0
+		}
+
+		// verbatim copy to the working buffer
+		if doRender {
+			work.Write(data[beg:end])
+		}
+		beg = end
+	}
+
+	if doRender {
+		block := p.addBlock(CodeBlock, work.Bytes()) // TODO: get rid of temp buffer
+		block.IsFenced = true
+		block.FenceLength = fenceLength
+		finalizeCodeBlock(block)
+	}
+
+	return beg
+}
+
+func unescapeChar(str []byte) []byte {
+	if str[0] == '\\' {
+		return []byte{str[1]}
+	}
+	return []byte(html.UnescapeString(string(str)))
+}
+
+func unescapeString(str []byte) []byte {
+	if reBackslashOrAmp.Match(str) {
+		return reEntityOrEscapedChar.ReplaceAllFunc(str, unescapeChar)
+	}
+	return str
+}
+
+func finalizeCodeBlock(block *Node) {
+	if block.IsFenced {
+		newlinePos := bytes.IndexByte(block.content, '\n')
+		firstLine := block.content[:newlinePos]
+		rest := block.content[newlinePos+1:]
+		block.Info = unescapeString(bytes.Trim(firstLine, "\n"))
+		block.Literal = rest
+	} else {
+		block.Literal = block.content
+	}
+	block.content = nil
+}
+
+func (p *Markdown) table(data []byte) int {
+	table := p.addBlock(Table, nil)
+	i, columns := p.tableHeader(data)
+	if i == 0 {
+		p.tip = table.Parent
+		table.Unlink()
+		return 0
+	}
+
+	p.addBlock(TableBody, nil)
+
+	for i < len(data) {
+		pipes, rowStart := 0, i
+		for ; i < len(data) && data[i] != '\n'; i++ {
+			if data[i] == '|' {
+				pipes++
+			}
+		}
+
+		if pipes == 0 {
+			i = rowStart
+			break
+		}
+
+		// include the newline in data sent to tableRow
+		if i < len(data) && data[i] == '\n' {
+			i++
+		}
+		p.tableRow(data[rowStart:i], columns, false)
+	}
+
+	return i
+}
+
+// check if the specified position is preceded by an odd number of backslashes
+func isBackslashEscaped(data []byte, i int) bool {
+	backslashes := 0
+	for i-backslashes-1 >= 0 && data[i-backslashes-1] == '\\' {
+		backslashes++
+	}
+	return backslashes&1 == 1
+}
+
+func (p *Markdown) tableHeader(data []byte) (size int, columns []CellAlignFlags) {
+	i := 0
+	colCount := 1
+	for i = 0; i < len(data) && data[i] != '\n'; i++ {
+		if data[i] == '|' && !isBackslashEscaped(data, i) {
+			colCount++
+		}
+	}
+
+	// doesn't look like a table header
+	if colCount == 1 {
+		return
+	}
+
+	// include the newline in the data sent to tableRow
+	j := i
+	if j < len(data) && data[j] == '\n' {
+		j++
+	}
+	header := data[:j]
+
+	// column count ignores pipes at beginning or end of line
+	if data[0] == '|' {
+		colCount--
+	}
+	if i > 2 && data[i-1] == '|' && !isBackslashEscaped(data, i-1) {
+		colCount--
+	}
+
+	columns = make([]CellAlignFlags, colCount)
+
+	// move on to the header underline
+	i++
+	if i >= len(data) {
+		return
+	}
+
+	if data[i] == '|' && !isBackslashEscaped(data, i) {
+		i++
+	}
+	i = skipChar(data, i, ' ')
+
+	// each column header is of form: / *:?-+:? *|/ with # dashes + # colons >= 3
+	// and trailing | optional on last column
+	col := 0
+	for i < len(data) && data[i] != '\n' {
+		dashes := 0
+
+		if data[i] == ':' {
+			i++
+			columns[col] |= TableAlignmentLeft
+			dashes++
+		}
+		for i < len(data) && data[i] == '-' {
+			i++
+			dashes++
+		}
+		if i < len(data) && data[i] == ':' {
+			i++
+			columns[col] |= TableAlignmentRight
+			dashes++
+		}
+		for i < len(data) && data[i] == ' ' {
+			i++
+		}
+		if i == len(data) {
+			return
+		}
+		// end of column test is messy
+		switch {
+		case dashes < 3:
+			// not a valid column
+			return
+
+		case data[i] == '|' && !isBackslashEscaped(data, i):
+			// marker found, now skip past trailing whitespace
+			col++
+			i++
+			for i < len(data) && data[i] == ' ' {
+				i++
+			}
+
+			// trailing junk found after last column
+			if col >= colCount && i < len(data) && data[i] != '\n' {
+				return
+			}
+
+		case (data[i] != '|' || isBackslashEscaped(data, i)) && col+1 < colCount:
+			// something else found where marker was required
+			return
+
+		case data[i] == '\n':
+			// marker is optional for the last column
+			col++
+
+		default:
+			// trailing junk found after last column
+			return
+		}
+	}
+	if col != colCount {
+		return
+	}
+
+	p.addBlock(TableHead, nil)
+	p.tableRow(header, columns, true)
+	size = i
+	if size < len(data) && data[size] == '\n' {
+		size++
+	}
+	return
+}
+
+func (p *Markdown) tableRow(data []byte, columns []CellAlignFlags, header bool) {
+	p.addBlock(TableRow, nil)
+	i, col := 0, 0
+
+	if data[i] == '|' && !isBackslashEscaped(data, i) {
+		i++
+	}
+
+	for col = 0; col < len(columns) && i < len(data); col++ {
+		for i < len(data) && data[i] == ' ' {
+			i++
+		}
+
+		cellStart := i
+
+		for i < len(data) && (data[i] != '|' || isBackslashEscaped(data, i)) && data[i] != '\n' {
+			i++
+		}
+
+		cellEnd := i
+
+		// skip the end-of-cell marker, possibly taking us past end of buffer
+		i++
+
+		for cellEnd > cellStart && cellEnd-1 < len(data) && data[cellEnd-1] == ' ' {
+			cellEnd--
+		}
+
+		cell := p.addBlock(TableCell, data[cellStart:cellEnd])
+		cell.IsHeader = header
+		cell.Align = columns[col]
+	}
+
+	// pad it out with empty columns to get the right number
+	for ; col < len(columns); col++ {
+		cell := p.addBlock(TableCell, nil)
+		cell.IsHeader = header
+		cell.Align = columns[col]
+	}
+
+	// silently ignore rows with too many cells
+}
+
+// returns blockquote prefix length
+func (p *Markdown) quotePrefix(data []byte) int {
+	i := 0
+	for i < 3 && i < len(data) && data[i] == ' ' {
+		i++
+	}
+	if i < len(data) && data[i] == '>' {
+		if i+1 < len(data) && data[i+1] == ' ' {
+			return i + 2
+		}
+		return i + 1
+	}
+	return 0
+}
+
+// blockquote ends with at least one blank line
+// followed by something without a blockquote prefix
+func (p *Markdown) terminateBlockquote(data []byte, beg, end int) bool {
+	if p.isEmpty(data[beg:]) <= 0 {
+		return false
+	}
+	if end >= len(data) {
+		return true
+	}
+	return p.quotePrefix(data[end:]) == 0 && p.isEmpty(data[end:]) == 0
+}
+
+// parse a blockquote fragment
+func (p *Markdown) quote(data []byte) int {
+	block := p.addBlock(BlockQuote, nil)
+	var raw bytes.Buffer
+	beg, end := 0, 0
+	for beg < len(data) {
+		end = beg
+		// Step over whole lines, collecting them. While doing that, check for
+		// fenced code and if one's found, incorporate it altogether,
+		// irregardless of any contents inside it
+		for end < len(data) && data[end] != '\n' {
+			if p.extensions&FencedCode != 0 {
+				if i := p.fencedCodeBlock(data[end:], false); i > 0 {
+					// -1 to compensate for the extra end++ after the loop:
+					end += i - 1
+					break
+				}
+			}
+			end++
+		}
+		if end < len(data) && data[end] == '\n' {
+			end++
+		}
+		if pre := p.quotePrefix(data[beg:]); pre > 0 {
+			// skip the prefix
+			beg += pre
+		} else if p.terminateBlockquote(data, beg, end) {
+			break
+		}
+		// this line is part of the blockquote
+		raw.Write(data[beg:end])
+		beg = end
+	}
+	p.block(raw.Bytes())
+	p.finalize(block)
+	return end
+}
+
+// returns prefix length for block code
+func (p *Markdown) codePrefix(data []byte) int {
+	if len(data) >= 1 && data[0] == '\t' {
+		return 1
+	}
+	if len(data) >= 4 && data[0] == ' ' && data[1] == ' ' && data[2] == ' ' && data[3] == ' ' {
+		return 4
+	}
+	return 0
+}
+
+func (p *Markdown) code(data []byte) int {
+	var work bytes.Buffer
+
+	i := 0
+	for i < len(data) {
+		beg := i
+		for i < len(data) && data[i] != '\n' {
+			i++
+		}
+		if i < len(data) && data[i] == '\n' {
+			i++
+		}
+
+		blankline := p.isEmpty(data[beg:i]) > 0
+		if pre := p.codePrefix(data[beg:i]); pre > 0 {
+			beg += pre
+		} else if !blankline {
+			// non-empty, non-prefixed line breaks the pre
+			i = beg
+			break
+		}
+
+		// verbatim copy to the working buffer
+		if blankline {
+			work.WriteByte('\n')
+		} else {
+			work.Write(data[beg:i])
+		}
+	}
+
+	// trim all the \n off the end of work
+	workbytes := work.Bytes()
+	eol := len(workbytes)
+	for eol > 0 && workbytes[eol-1] == '\n' {
+		eol--
+	}
+	if eol != len(workbytes) {
+		work.Truncate(eol)
+	}
+
+	work.WriteByte('\n')
+
+	block := p.addBlock(CodeBlock, work.Bytes()) // TODO: get rid of temp buffer
+	block.IsFenced = false
+	finalizeCodeBlock(block)
+
+	return i
+}
+
+// returns unordered list item prefix
+func (p *Markdown) uliPrefix(data []byte) int {
+	i := 0
+	// start with up to 3 spaces
+	for i < len(data) && i < 3 && data[i] == ' ' {
+		i++
+	}
+	if i >= len(data)-1 {
+		return 0
+	}
+	// need one of {'*', '+', '-'} followed by a space or a tab
+	if (data[i] != '*' && data[i] != '+' && data[i] != '-') ||
+		(data[i+1] != ' ' && data[i+1] != '\t') {
+		return 0
+	}
+	return i + 2
+}
+
+// returns ordered list item prefix
+func (p *Markdown) oliPrefix(data []byte) int {
+	i := 0
+
+	// start with up to 3 spaces
+	for i < 3 && i < len(data) && data[i] == ' ' {
+		i++
+	}
+
+	// count the digits
+	start := i
+	for i < len(data) && data[i] >= '0' && data[i] <= '9' {
+		i++
+	}
+	if start == i || i >= len(data)-1 {
+		return 0
+	}
+
+	// we need >= 1 digits followed by a dot and a space or a tab
+	if data[i] != '.' || !(data[i+1] == ' ' || data[i+1] == '\t') {
+		return 0
+	}
+	return i + 2
+}
+
+// returns definition list item prefix
+func (p *Markdown) dliPrefix(data []byte) int {
+	if len(data) < 2 {
+		return 0
+	}
+	i := 0
+	// need a ':' followed by a space or a tab
+	if data[i] != ':' || !(data[i+1] == ' ' || data[i+1] == '\t') {
+		return 0
+	}
+	for i < len(data) && data[i] == ' ' {
+		i++
+	}
+	return i + 2
+}
+
+// parse ordered or unordered list block
+func (p *Markdown) list(data []byte, flags ListType) int {
+	i := 0
+	flags |= ListItemBeginningOfList
+	block := p.addBlock(List, nil)
+	block.ListFlags = flags
+	block.Tight = true
+
+	for i < len(data) {
+		skip := p.listItem(data[i:], &flags)
+		if flags&ListItemContainsBlock != 0 {
+			block.ListData.Tight = false
+		}
+		i += skip
+		if skip == 0 || flags&ListItemEndOfList != 0 {
+			break
+		}
+		flags &= ^ListItemBeginningOfList
+	}
+
+	above := block.Parent
+	finalizeList(block)
+	p.tip = above
+	return i
+}
+
+// Returns true if the list item is not the same type as its parent list
+func (p *Markdown) listTypeChanged(data []byte, flags *ListType) bool {
+	if p.dliPrefix(data) > 0 && *flags&ListTypeDefinition == 0 {
+		return true
+	} else if p.oliPrefix(data) > 0 && *flags&ListTypeOrdered == 0 {
+		return true
+	} else if p.uliPrefix(data) > 0 && (*flags&ListTypeOrdered != 0 || *flags&ListTypeDefinition != 0) {
+		return true
+	}
+	return false
+}
+
+// Returns true if block ends with a blank line, descending if needed
+// into lists and sublists.
+func endsWithBlankLine(block *Node) bool {
+	// TODO: figure this out. Always false now.
+	for block != nil {
+		//if block.lastLineBlank {
+		//return true
+		//}
+		t := block.Type
+		if t == List || t == Item {
+			block = block.LastChild
+		} else {
+			break
+		}
+	}
+	return false
+}
+
+func finalizeList(block *Node) {
+	block.open = false
+	item := block.FirstChild
+	for item != nil {
+		// check for non-final list item ending with blank line:
+		if endsWithBlankLine(item) && item.Next != nil {
+			block.ListData.Tight = false
+			break
+		}
+		// recurse into children of list item, to see if there are spaces
+		// between any of them:
+		subItem := item.FirstChild
+		for subItem != nil {
+			if endsWithBlankLine(subItem) && (item.Next != nil || subItem.Next != nil) {
+				block.ListData.Tight = false
+				break
+			}
+			subItem = subItem.Next
+		}
+		item = item.Next
+	}
+}
+
+// Parse a single list item.
+// Assumes initial prefix is already removed if this is a sublist.
+func (p *Markdown) listItem(data []byte, flags *ListType) int {
+	// keep track of the indentation of the first line
+	itemIndent := 0
+	if data[0] == '\t' {
+		itemIndent += 4
+	} else {
+		for itemIndent < 3 && data[itemIndent] == ' ' {
+			itemIndent++
+		}
+	}
+
+	var bulletChar byte = '*'
+	i := p.uliPrefix(data)
+	if i == 0 {
+		i = p.oliPrefix(data)
+	} else {
+		bulletChar = data[i-2]
+	}
+	if i == 0 {
+		i = p.dliPrefix(data)
+		// reset definition term flag
+		if i > 0 {
+			*flags &= ^ListTypeTerm
+		}
+	}
+	if i == 0 {
+		// if in definition list, set term flag and continue
+		if *flags&ListTypeDefinition != 0 {
+			*flags |= ListTypeTerm
+		} else {
+			return 0
+		}
+	}
+
+	// skip leading whitespace on first line
+	for i < len(data) && data[i] == ' ' {
+		i++
+	}
+
+	// find the end of the line
+	line := i
+	for i > 0 && i < len(data) && data[i-1] != '\n' {
+		i++
+	}
+
+	// get working buffer
+	var raw bytes.Buffer
+
+	// put the first line into the working buffer
+	raw.Write(data[line:i])
+	line = i
+
+	// process the following lines
+	containsBlankLine := false
+	sublist := 0
+	codeBlockMarker := ""
+
+gatherlines:
+	for line < len(data) {
+		i++
+
+		// find the end of this line
+		for i < len(data) && data[i-1] != '\n' {
+			i++
+		}
+
+		// if it is an empty line, guess that it is part of this item
+		// and move on to the next line
+		if p.isEmpty(data[line:i]) > 0 {
+			containsBlankLine = true
+			line = i
+			continue
+		}
+
+		// calculate the indentation
+		indent := 0
+		indentIndex := 0
+		if data[line] == '\t' {
+			indentIndex++
+			indent += 4
+		} else {
+			for indent < 4 && line+indent < i && data[line+indent] == ' ' {
+				indent++
+				indentIndex++
+			}
+		}
+
+		chunk := data[line+indentIndex : i]
+
+		if p.extensions&FencedCode != 0 {
+			// determine if in or out of codeblock
+			// if in codeblock, ignore normal list processing
+			_, marker := isFenceLine(chunk, nil, codeBlockMarker)
+			if marker != "" {
+				if codeBlockMarker == "" {
+					// start of codeblock
+					codeBlockMarker = marker
+				} else {
+					// end of codeblock.
+					codeBlockMarker = ""
+				}
+			}
+			// we are in a codeblock, write line, and continue
+			if codeBlockMarker != "" || marker != "" {
+				raw.Write(data[line+indentIndex : i])
+				line = i
+				continue gatherlines
+			}
+		}
+
+		// evaluate how this line fits in
+		switch {
+		// is this a nested list item?
+		case (p.uliPrefix(chunk) > 0 && !p.isHRule(chunk)) ||
+			p.oliPrefix(chunk) > 0 ||
+			p.dliPrefix(chunk) > 0:
+
+			// to be a nested list, it must be indented more
+			// if not, it is either a different kind of list
+			// or the next item in the same list
+			if indent <= itemIndent {
+				if p.listTypeChanged(chunk, flags) {
+					*flags |= ListItemEndOfList
+				} else if containsBlankLine {
+					*flags |= ListItemContainsBlock
+				}
+
+				break gatherlines
+			}
+
+			if containsBlankLine {
+				*flags |= ListItemContainsBlock
+			}
+
+			// is this the first item in the nested list?
+			if sublist == 0 {
+				sublist = raw.Len()
+			}
+
+		// is this a nested prefix heading?
+		case p.isPrefixHeading(chunk):
+			// if the heading is not indented, it is not nested in the list
+			// and thus ends the list
+			if containsBlankLine && indent < 4 {
+				*flags |= ListItemEndOfList
+				break gatherlines
+			}
+			*flags |= ListItemContainsBlock
+
+		// anything following an empty line is only part
+		// of this item if it is indented 4 spaces
+		// (regardless of the indentation of the beginning of the item)
+		case containsBlankLine && indent < 4:
+			if *flags&ListTypeDefinition != 0 && i < len(data)-1 {
+				// is the next item still a part of this list?
+				next := i
+				for next < len(data) && data[next] != '\n' {
+					next++
+				}
+				for next < len(data)-1 && data[next] == '\n' {
+					next++
+				}
+				if i < len(data)-1 && data[i] != ':' && data[next] != ':' {
+					*flags |= ListItemEndOfList
+				}
+			} else {
+				*flags |= ListItemEndOfList
+			}
+			break gatherlines
+
+		// a blank line means this should be parsed as a block
+		case containsBlankLine:
+			raw.WriteByte('\n')
+			*flags |= ListItemContainsBlock
+		}
+
+		// if this line was preceded by one or more blanks,
+		// re-introduce the blank into the buffer
+		if containsBlankLine {
+			containsBlankLine = false
+			raw.WriteByte('\n')
+		}
+
+		// add the line into the working buffer without prefix
+		raw.Write(data[line+indentIndex : i])
+
+		line = i
+	}
+
+	rawBytes := raw.Bytes()
+
+	block := p.addBlock(Item, nil)
+	block.ListFlags = *flags
+	block.Tight = false
+	block.BulletChar = bulletChar
+	block.Delimiter = '.' // Only '.' is possible in Markdown, but ')' will also be possible in CommonMark
+
+	// render the contents of the list item
+	if *flags&ListItemContainsBlock != 0 && *flags&ListTypeTerm == 0 {
+		// intermediate render of block item, except for definition term
+		if sublist > 0 {
+			p.block(rawBytes[:sublist])
+			p.block(rawBytes[sublist:])
+		} else {
+			p.block(rawBytes)
+		}
+	} else {
+		// intermediate render of inline item
+		if sublist > 0 {
+			child := p.addChild(Paragraph, 0)
+			child.content = rawBytes[:sublist]
+			p.block(rawBytes[sublist:])
+		} else {
+			child := p.addChild(Paragraph, 0)
+			child.content = rawBytes
+		}
+	}
+	return line
+}
+
+// render a single paragraph that has already been parsed out
+func (p *Markdown) renderParagraph(data []byte) {
+	if len(data) == 0 {
+		return
+	}
+
+	// trim leading spaces
+	beg := 0
+	for data[beg] == ' ' {
+		beg++
+	}
+
+	end := len(data)
+	// trim trailing newline
+	if data[len(data)-1] == '\n' {
+		end--
+	}
+
+	// trim trailing spaces
+	for end > beg && data[end-1] == ' ' {
+		end--
+	}
+
+	p.addBlock(Paragraph, data[beg:end])
+}
+
+func (p *Markdown) paragraph(data []byte) int {
+	// prev: index of 1st char of previous line
+	// line: index of 1st char of current line
+	// i: index of cursor/end of current line
+	var prev, line, i int
+	tabSize := TabSizeDefault
+	if p.extensions&TabSizeEight != 0 {
+		tabSize = TabSizeDouble
+	}
+	// keep going until we find something to mark the end of the paragraph
+	for i < len(data) {
+		// mark the beginning of the current line
+		prev = line
+		current := data[i:]
+		line = i
+
+		// did we find a reference or a footnote? If so, end a paragraph
+		// preceding it and report that we have consumed up to the end of that
+		// reference:
+		if refEnd := isReference(p, current, tabSize); refEnd > 0 {
+			p.renderParagraph(data[:i])
+			return i + refEnd
+		}
+
+		// did we find a blank line marking the end of the paragraph?
+		if n := p.isEmpty(current); n > 0 {
+			// did this blank line followed by a definition list item?
+			if p.extensions&DefinitionLists != 0 {
+				if i < len(data)-1 && data[i+1] == ':' {
+					return p.list(data[prev:], ListTypeDefinition)
+				}
+			}
+
+			p.renderParagraph(data[:i])
+			return i + n
+		}
+
+		// an underline under some text marks a heading, so our paragraph ended on prev line
+		if i > 0 {
+			if level := p.isUnderlinedHeading(current); level > 0 {
+				// render the paragraph
+				p.renderParagraph(data[:prev])
+
+				// ignore leading and trailing whitespace
+				eol := i - 1
+				for prev < eol && data[prev] == ' ' {
+					prev++
+				}
+				for eol > prev && data[eol-1] == ' ' {
+					eol--
+				}
+
+				id := ""
+				if p.extensions&AutoHeadingIDs != 0 {
+					id = SanitizedAnchorName(string(data[prev:eol]))
+				}
+
+				block := p.addBlock(Heading, data[prev:eol])
+				block.Level = level
+				block.HeadingID = id
+
+				// find the end of the underline
+				for i < len(data) && data[i] != '\n' {
+					i++
+				}
+				return i
+			}
+		}
+
+		// if the next line starts a block of HTML, then the paragraph ends here
+		if p.extensions&LaxHTMLBlocks != 0 {
+			if data[i] == '<' && p.html(current, false) > 0 {
+				// rewind to before the HTML block
+				p.renderParagraph(data[:i])
+				return i
+			}
+		}
+
+		// if there's a prefixed heading or a horizontal rule after this, paragraph is over
+		if p.isPrefixHeading(current) || p.isHRule(current) {
+			p.renderParagraph(data[:i])
+			return i
+		}
+
+		// if there's a fenced code block, paragraph is over
+		if p.extensions&FencedCode != 0 {
+			if p.fencedCodeBlock(current, false) > 0 {
+				p.renderParagraph(data[:i])
+				return i
+			}
+		}
+
+		// if there's a definition list item, prev line is a definition term
+		if p.extensions&DefinitionLists != 0 {
+			if p.dliPrefix(current) != 0 {
+				ret := p.list(data[prev:], ListTypeDefinition)
+				return ret
+			}
+		}
+
+		// if there's a list after this, paragraph is over
+		if p.extensions&NoEmptyLineBeforeBlock != 0 {
+			if p.uliPrefix(current) != 0 ||
+				p.oliPrefix(current) != 0 ||
+				p.quotePrefix(current) != 0 ||
+				p.codePrefix(current) != 0 {
+				p.renderParagraph(data[:i])
+				return i
+			}
+		}
+
+		// otherwise, scan to the beginning of the next line
+		nl := bytes.IndexByte(data[i:], '\n')
+		if nl >= 0 {
+			i += nl + 1
+		} else {
+			i += len(data[i:])
+		}
+	}
+
+	p.renderParagraph(data[:i])
+	return i
+}
+
+func skipChar(data []byte, start int, char byte) int {
+	i := start
+	for i < len(data) && data[i] == char {
+		i++
+	}
+	return i
+}
+
+func skipUntilChar(text []byte, start int, char byte) int {
+	i := start
+	for i < len(text) && text[i] != char {
+		i++
+	}
+	return i
+}
+
+// SanitizedAnchorName returns a sanitized anchor name for the given text.
+//
+// It implements the algorithm specified in the package comment.
+func SanitizedAnchorName(text string) string {
+	var anchorName []rune
+	futureDash := false
+	for _, r := range text {
+		switch {
+		case unicode.IsLetter(r) || unicode.IsNumber(r):
+			if futureDash && len(anchorName) > 0 {
+				anchorName = append(anchorName, '-')
+			}
+			futureDash = false
+			anchorName = append(anchorName, unicode.ToLower(r))
+		default:
+			futureDash = true
+		}
+	}
+	return string(anchorName)
+}
diff --git a/vendor/github.com/russross/blackfriday/v2/doc.go b/vendor/github.com/russross/blackfriday/v2/doc.go
new file mode 100644
index 000000000000..57ff152a0568
--- /dev/null
+++ b/vendor/github.com/russross/blackfriday/v2/doc.go
@@ -0,0 +1,46 @@
+// Package blackfriday is a markdown processor.
+//
+// It translates plain text with simple formatting rules into an AST, which can
+// then be further processed to HTML (provided by Blackfriday itself) or other
+// formats (provided by the community).
+//
+// The simplest way to invoke Blackfriday is to call the Run function. It will
+// take a text input and produce a text output in HTML (or other format).
+//
+// A slightly more sophisticated way to use Blackfriday is to create a Markdown
+// processor and to call Parse, which returns a syntax tree for the input
+// document. You can leverage Blackfriday's parsing for content extraction from
+// markdown documents. You can assign a custom renderer and set various options
+// to the Markdown processor.
+//
+// If you're interested in calling Blackfriday from command line, see
+// https://github.com/russross/blackfriday-tool.
+//
+// Sanitized Anchor Names
+//
+// Blackfriday includes an algorithm for creating sanitized anchor names
+// corresponding to a given input text. This algorithm is used to create
+// anchors for headings when AutoHeadingIDs extension is enabled. The
+// algorithm is specified below, so that other packages can create
+// compatible anchor names and links to those anchors.
+//
+// The algorithm iterates over the input text, interpreted as UTF-8,
+// one Unicode code point (rune) at a time. All runes that are letters (category L)
+// or numbers (category N) are considered valid characters. They are mapped to
+// lower case, and included in the output. All other runes are considered
+// invalid characters. Invalid characters that precede the first valid character,
+// as well as invalid character that follow the last valid character
+// are dropped completely. All other sequences of invalid characters
+// between two valid characters are replaced with a single dash character '-'.
+//
+// SanitizedAnchorName exposes this functionality, and can be used to
+// create compatible links to the anchor names generated by blackfriday.
+// This algorithm is also implemented in a small standalone package at
+// github.com/shurcooL/sanitized_anchor_name. It can be useful for clients
+// that want a small package and don't need full functionality of blackfriday.
+package blackfriday
+
+// NOTE: Keep Sanitized Anchor Name algorithm in sync with package
+//       github.com/shurcooL/sanitized_anchor_name.
+//       Otherwise, users of sanitized_anchor_name will get anchor names
+//       that are incompatible with those generated by blackfriday.
diff --git a/vendor/github.com/russross/blackfriday/v2/entities.go b/vendor/github.com/russross/blackfriday/v2/entities.go
new file mode 100644
index 000000000000..a2c3edb691c8
--- /dev/null
+++ b/vendor/github.com/russross/blackfriday/v2/entities.go
@@ -0,0 +1,2236 @@
+package blackfriday
+
+// Extracted from https://html.spec.whatwg.org/multipage/entities.json
+var entities = map[string]bool{
+	"&AElig":                            true,
+	"&AElig;":                           true,
+	"&AMP":                              true,
+	"&AMP;":                             true,
+	"&Aacute":                           true,
+	"&Aacute;":                          true,
+	"&Abreve;":                          true,
+	"&Acirc":                            true,
+	"&Acirc;":                           true,
+	"&Acy;":                             true,
+	"&Afr;":                             true,
+	"&Agrave":                           true,
+	"&Agrave;":                          true,
+	"&Alpha;":                           true,
+	"&Amacr;":                           true,
+	"&And;":                             true,
+	"&Aogon;":                           true,
+	"&Aopf;":                            true,
+	"&ApplyFunction;":                   true,
+	"&Aring":                            true,
+	"&Aring;":                           true,
+	"&Ascr;":                            true,
+	"&Assign;":                          true,
+	"&Atilde":                           true,
+	"&Atilde;":                          true,
+	"&Auml":                             true,
+	"&Auml;":                            true,
+	"&Backslash;":                       true,
+	"&Barv;":                            true,
+	"&Barwed;":                          true,
+	"&Bcy;":                             true,
+	"&Because;":                         true,
+	"&Bernoullis;":                      true,
+	"&Beta;":                            true,
+	"&Bfr;":                             true,
+	"&Bopf;":                            true,
+	"&Breve;":                           true,
+	"&Bscr;":                            true,
+	"&Bumpeq;":                          true,
+	"&CHcy;":                            true,
+	"&COPY":                             true,
+	"&COPY;":                            true,
+	"&Cacute;":                          true,
+	"&Cap;":                             true,
+	"&CapitalDifferentialD;":            true,
+	"&Cayleys;":                         true,
+	"&Ccaron;":                          true,
+	"&Ccedil":                           true,
+	"&Ccedil;":                          true,
+	"&Ccirc;":                           true,
+	"&Cconint;":                         true,
+	"&Cdot;":                            true,
+	"&Cedilla;":                         true,
+	"&CenterDot;":                       true,
+	"&Cfr;":                             true,
+	"&Chi;":                             true,
+	"&CircleDot;":                       true,
+	"&CircleMinus;":                     true,
+	"&CirclePlus;":                      true,
+	"&CircleTimes;":                     true,
+	"&ClockwiseContourIntegral;":        true,
+	"&CloseCurlyDoubleQuote;":           true,
+	"&CloseCurlyQuote;":                 true,
+	"&Colon;":                           true,
+	"&Colone;":                          true,
+	"&Congruent;":                       true,
+	"&Conint;":                          true,
+	"&ContourIntegral;":                 true,
+	"&Copf;":                            true,
+	"&Coproduct;":                       true,
+	"&CounterClockwiseContourIntegral;": true,
+	"&Cross;":                           true,
+	"&Cscr;":                            true,
+	"&Cup;":                             true,
+	"&CupCap;":                          true,
+	"&DD;":                              true,
+	"&DDotrahd;":                        true,
+	"&DJcy;":                            true,
+	"&DScy;":                            true,
+	"&DZcy;":                            true,
+	"&Dagger;":                          true,
+	"&Darr;":                            true,
+	"&Dashv;":                           true,
+	"&Dcaron;":                          true,
+	"&Dcy;":                             true,
+	"&Del;":                             true,
+	"&Delta;":                           true,
+	"&Dfr;":                             true,
+	"&DiacriticalAcute;":                true,
+	"&DiacriticalDot;":                  true,
+	"&DiacriticalDoubleAcute;":          true,
+	"&DiacriticalGrave;":                true,
+	"&DiacriticalTilde;":                true,
+	"&Diamond;":                         true,
+	"&DifferentialD;":                   true,
+	"&Dopf;":                            true,
+	"&Dot;":                             true,
+	"&DotDot;":                          true,
+	"&DotEqual;":                        true,
+	"&DoubleContourIntegral;":           true,
+	"&DoubleDot;":                       true,
+	"&DoubleDownArrow;":                 true,
+	"&DoubleLeftArrow;":                 true,
+	"&DoubleLeftRightArrow;":            true,
+	"&DoubleLeftTee;":                   true,
+	"&DoubleLongLeftArrow;":             true,
+	"&DoubleLongLeftRightArrow;":        true,
+	"&DoubleLongRightArrow;":            true,
+	"&DoubleRightArrow;":                true,
+	"&DoubleRightTee;":                  true,
+	"&DoubleUpArrow;":                   true,
+	"&DoubleUpDownArrow;":               true,
+	"&DoubleVerticalBar;":               true,
+	"&DownArrow;":                       true,
+	"&DownArrowBar;":                    true,
+	"&DownArrowUpArrow;":                true,
+	"&DownBreve;":                       true,
+	"&DownLeftRightVector;":             true,
+	"&DownLeftTeeVector;":               true,
+	"&DownLeftVector;":                  true,
+	"&DownLeftVectorBar;":               true,
+	"&DownRightTeeVector;":              true,
+	"&DownRightVector;":                 true,
+	"&DownRightVectorBar;":              true,
+	"&DownTee;":                         true,
+	"&DownTeeArrow;":                    true,
+	"&Downarrow;":                       true,
+	"&Dscr;":                            true,
+	"&Dstrok;":                          true,
+	"&ENG;":                             true,
+	"&ETH":                              true,
+	"&ETH;":                             true,
+	"&Eacute":                           true,
+	"&Eacute;":                          true,
+	"&Ecaron;":                          true,
+	"&Ecirc":                            true,
+	"&Ecirc;":                           true,
+	"&Ecy;":                             true,
+	"&Edot;":                            true,
+	"&Efr;":                             true,
+	"&Egrave":                           true,
+	"&Egrave;":                          true,
+	"&Element;":                         true,
+	"&Emacr;":                           true,
+	"&EmptySmallSquare;":                true,
+	"&EmptyVerySmallSquare;":            true,
+	"&Eogon;":                           true,
+	"&Eopf;":                            true,
+	"&Epsilon;":                         true,
+	"&Equal;":                           true,
+	"&EqualTilde;":                      true,
+	"&Equilibrium;":                     true,
+	"&Escr;":                            true,
+	"&Esim;":                            true,
+	"&Eta;":                             true,
+	"&Euml":                             true,
+	"&Euml;":                            true,
+	"&Exists;":                          true,
+	"&ExponentialE;":                    true,
+	"&Fcy;":                             true,
+	"&Ffr;":                             true,
+	"&FilledSmallSquare;":               true,
+	"&FilledVerySmallSquare;":           true,
+	"&Fopf;":                            true,
+	"&ForAll;":                          true,
+	"&Fouriertrf;":                      true,
+	"&Fscr;":                            true,
+	"&GJcy;":                            true,
+	"&GT":                               true,
+	"&GT;":                              true,
+	"&Gamma;":                           true,
+	"&Gammad;":                          true,
+	"&Gbreve;":                          true,
+	"&Gcedil;":                          true,
+	"&Gcirc;":                           true,
+	"&Gcy;":                             true,
+	"&Gdot;":                            true,
+	"&Gfr;":                             true,
+	"&Gg;":                              true,
+	"&Gopf;":                            true,
+	"&GreaterEqual;":                    true,
+	"&GreaterEqualLess;":                true,
+	"&GreaterFullEqual;":                true,
+	"&GreaterGreater;":                  true,
+	"&GreaterLess;":                     true,
+	"&GreaterSlantEqual;":               true,
+	"&GreaterTilde;":                    true,
+	"&Gscr;":                            true,
+	"&Gt;":                              true,
+	"&HARDcy;":                          true,
+	"&Hacek;":                           true,
+	"&Hat;":                             true,
+	"&Hcirc;":                           true,
+	"&Hfr;":                             true,
+	"&HilbertSpace;":                    true,
+	"&Hopf;":                            true,
+	"&HorizontalLine;":                  true,
+	"&Hscr;":                            true,
+	"&Hstrok;":                          true,
+	"&HumpDownHump;":                    true,
+	"&HumpEqual;":                       true,
+	"&IEcy;":                            true,
+	"&IJlig;":                           true,
+	"&IOcy;":                            true,
+	"&Iacute":                           true,
+	"&Iacute;":                          true,
+	"&Icirc":                            true,
+	"&Icirc;":                           true,
+	"&Icy;":                             true,
+	"&Idot;":                            true,
+	"&Ifr;":                             true,
+	"&Igrave":                           true,
+	"&Igrave;":                          true,
+	"&Im;":                              true,
+	"&Imacr;":                           true,
+	"&ImaginaryI;":                      true,
+	"&Implies;":                         true,
+	"&Int;":                             true,
+	"&Integral;":                        true,
+	"&Intersection;":                    true,
+	"&InvisibleComma;":                  true,
+	"&InvisibleTimes;":                  true,
+	"&Iogon;":                           true,
+	"&Iopf;":                            true,
+	"&Iota;":                            true,
+	"&Iscr;":                            true,
+	"&Itilde;":                          true,
+	"&Iukcy;":                           true,
+	"&Iuml":                             true,
+	"&Iuml;":                            true,
+	"&Jcirc;":                           true,
+	"&Jcy;":                             true,
+	"&Jfr;":                             true,
+	"&Jopf;":                            true,
+	"&Jscr;":                            true,
+	"&Jsercy;":                          true,
+	"&Jukcy;":                           true,
+	"&KHcy;":                            true,
+	"&KJcy;":                            true,
+	"&Kappa;":                           true,
+	"&Kcedil;":                          true,
+	"&Kcy;":                             true,
+	"&Kfr;":                             true,
+	"&Kopf;":                            true,
+	"&Kscr;":                            true,
+	"&LJcy;":                            true,
+	"&LT":                               true,
+	"&LT;":                              true,
+	"&Lacute;":                          true,
+	"&Lambda;":                          true,
+	"&Lang;":                            true,
+	"&Laplacetrf;":                      true,
+	"&Larr;":                            true,
+	"&Lcaron;":                          true,
+	"&Lcedil;":                          true,
+	"&Lcy;":                             true,
+	"&LeftAngleBracket;":                true,
+	"&LeftArrow;":                       true,
+	"&LeftArrowBar;":                    true,
+	"&LeftArrowRightArrow;":             true,
+	"&LeftCeiling;":                     true,
+	"&LeftDoubleBracket;":               true,
+	"&LeftDownTeeVector;":               true,
+	"&LeftDownVector;":                  true,
+	"&LeftDownVectorBar;":               true,
+	"&LeftFloor;":                       true,
+	"&LeftRightArrow;":                  true,
+	"&LeftRightVector;":                 true,
+	"&LeftTee;":                         true,
+	"&LeftTeeArrow;":                    true,
+	"&LeftTeeVector;":                   true,
+	"&LeftTriangle;":                    true,
+	"&LeftTriangleBar;":                 true,
+	"&LeftTriangleEqual;":               true,
+	"&LeftUpDownVector;":                true,
+	"&LeftUpTeeVector;":                 true,
+	"&LeftUpVector;":                    true,
+	"&LeftUpVectorBar;":                 true,
+	"&LeftVector;":                      true,
+	"&LeftVectorBar;":                   true,
+	"&Leftarrow;":                       true,
+	"&Leftrightarrow;":                  true,
+	"&LessEqualGreater;":                true,
+	"&LessFullEqual;":                   true,
+	"&LessGreater;":                     true,
+	"&LessLess;":                        true,
+	"&LessSlantEqual;":                  true,
+	"&LessTilde;":                       true,
+	"&Lfr;":                             true,
+	"&Ll;":                              true,
+	"&Lleftarrow;":                      true,
+	"&Lmidot;":                          true,
+	"&LongLeftArrow;":                   true,
+	"&LongLeftRightArrow;":              true,
+	"&LongRightArrow;":                  true,
+	"&Longleftarrow;":                   true,
+	"&Longleftrightarrow;":              true,
+	"&Longrightarrow;":                  true,
+	"&Lopf;":                            true,
+	"&LowerLeftArrow;":                  true,
+	"&LowerRightArrow;":                 true,
+	"&Lscr;":                            true,
+	"&Lsh;":                             true,
+	"&Lstrok;":                          true,
+	"&Lt;":                              true,
+	"&Map;":                             true,
+	"&Mcy;":                             true,
+	"&MediumSpace;":                     true,
+	"&Mellintrf;":                       true,
+	"&Mfr;":                             true,
+	"&MinusPlus;":                       true,
+	"&Mopf;":                            true,
+	"&Mscr;":                            true,
+	"&Mu;":                              true,
+	"&NJcy;":                            true,
+	"&Nacute;":                          true,
+	"&Ncaron;":                          true,
+	"&Ncedil;":                          true,
+	"&Ncy;":                             true,
+	"&NegativeMediumSpace;":             true,
+	"&NegativeThickSpace;":              true,
+	"&NegativeThinSpace;":               true,
+	"&NegativeVeryThinSpace;":           true,
+	"&NestedGreaterGreater;":            true,
+	"&NestedLessLess;":                  true,
+	"&NewLine;":                         true,
+	"&Nfr;":                             true,
+	"&NoBreak;":                         true,
+	"&NonBreakingSpace;":                true,
+	"&Nopf;":                            true,
+	"&Not;":                             true,
+	"&NotCongruent;":                    true,
+	"&NotCupCap;":                       true,
+	"&NotDoubleVerticalBar;":            true,
+	"&NotElement;":                      true,
+	"&NotEqual;":                        true,
+	"&NotEqualTilde;":                   true,
+	"&NotExists;":                       true,
+	"&NotGreater;":                      true,
+	"&NotGreaterEqual;":                 true,
+	"&NotGreaterFullEqual;":             true,
+	"&NotGreaterGreater;":               true,
+	"&NotGreaterLess;":                  true,
+	"&NotGreaterSlantEqual;":            true,
+	"&NotGreaterTilde;":                 true,
+	"&NotHumpDownHump;":                 true,
+	"&NotHumpEqual;":                    true,
+	"&NotLeftTriangle;":                 true,
+	"&NotLeftTriangleBar;":              true,
+	"&NotLeftTriangleEqual;":            true,
+	"&NotLess;":                         true,
+	"&NotLessEqual;":                    true,
+	"&NotLessGreater;":                  true,
+	"&NotLessLess;":                     true,
+	"&NotLessSlantEqual;":               true,
+	"&NotLessTilde;":                    true,
+	"&NotNestedGreaterGreater;":         true,
+	"&NotNestedLessLess;":               true,
+	"&NotPrecedes;":                     true,
+	"&NotPrecedesEqual;":                true,
+	"&NotPrecedesSlantEqual;":           true,
+	"&NotReverseElement;":               true,
+	"&NotRightTriangle;":                true,
+	"&NotRightTriangleBar;":             true,
+	"&NotRightTriangleEqual;":           true,
+	"&NotSquareSubset;":                 true,
+	"&NotSquareSubsetEqual;":            true,
+	"&NotSquareSuperset;":               true,
+	"&NotSquareSupersetEqual;":          true,
+	"&NotSubset;":                       true,
+	"&NotSubsetEqual;":                  true,
+	"&NotSucceeds;":                     true,
+	"&NotSucceedsEqual;":                true,
+	"&NotSucceedsSlantEqual;":           true,
+	"&NotSucceedsTilde;":                true,
+	"&NotSuperset;":                     true,
+	"&NotSupersetEqual;":                true,
+	"&NotTilde;":                        true,
+	"&NotTildeEqual;":                   true,
+	"&NotTildeFullEqual;":               true,
+	"&NotTildeTilde;":                   true,
+	"&NotVerticalBar;":                  true,
+	"&Nscr;":                            true,
+	"&Ntilde":                           true,
+	"&Ntilde;":                          true,
+	"&Nu;":                              true,
+	"&OElig;":                           true,
+	"&Oacute":                           true,
+	"&Oacute;":                          true,
+	"&Ocirc":                            true,
+	"&Ocirc;":                           true,
+	"&Ocy;":                             true,
+	"&Odblac;":                          true,
+	"&Ofr;":                             true,
+	"&Ograve":                           true,
+	"&Ograve;":                          true,
+	"&Omacr;":                           true,
+	"&Omega;":                           true,
+	"&Omicron;":                         true,
+	"&Oopf;":                            true,
+	"&OpenCurlyDoubleQuote;":            true,
+	"&OpenCurlyQuote;":                  true,
+	"&Or;":                              true,
+	"&Oscr;":                            true,
+	"&Oslash":                           true,
+	"&Oslash;":                          true,
+	"&Otilde":                           true,
+	"&Otilde;":                          true,
+	"&Otimes;":                          true,
+	"&Ouml":                             true,
+	"&Ouml;":                            true,
+	"&OverBar;":                         true,
+	"&OverBrace;":                       true,
+	"&OverBracket;":                     true,
+	"&OverParenthesis;":                 true,
+	"&PartialD;":                        true,
+	"&Pcy;":                             true,
+	"&Pfr;":                             true,
+	"&Phi;":                             true,
+	"&Pi;":                              true,
+	"&PlusMinus;":                       true,
+	"&Poincareplane;":                   true,
+	"&Popf;":                            true,
+	"&Pr;":                              true,
+	"&Precedes;":                        true,
+	"&PrecedesEqual;":                   true,
+	"&PrecedesSlantEqual;":              true,
+	"&PrecedesTilde;":                   true,
+	"&Prime;":                           true,
+	"&Product;":                         true,
+	"&Proportion;":                      true,
+	"&Proportional;":                    true,
+	"&Pscr;":                            true,
+	"&Psi;":                             true,
+	"&QUOT":                             true,
+	"&QUOT;":                            true,
+	"&Qfr;":                             true,
+	"&Qopf;":                            true,
+	"&Qscr;":                            true,
+	"&RBarr;":                           true,
+	"&REG":                              true,
+	"&REG;":                             true,
+	"&Racute;":                          true,
+	"&Rang;":                            true,
+	"&Rarr;":                            true,
+	"&Rarrtl;":                          true,
+	"&Rcaron;":                          true,
+	"&Rcedil;":                          true,
+	"&Rcy;":                             true,
+	"&Re;":                              true,
+	"&ReverseElement;":                  true,
+	"&ReverseEquilibrium;":              true,
+	"&ReverseUpEquilibrium;":            true,
+	"&Rfr;":                             true,
+	"&Rho;":                             true,
+	"&RightAngleBracket;":               true,
+	"&RightArrow;":                      true,
+	"&RightArrowBar;":                   true,
+	"&RightArrowLeftArrow;":             true,
+	"&RightCeiling;":                    true,
+	"&RightDoubleBracket;":              true,
+	"&RightDownTeeVector;":              true,
+	"&RightDownVector;":                 true,
+	"&RightDownVectorBar;":              true,
+	"&RightFloor;":                      true,
+	"&RightTee;":                        true,
+	"&RightTeeArrow;":                   true,
+	"&RightTeeVector;":                  true,
+	"&RightTriangle;":                   true,
+	"&RightTriangleBar;":                true,
+	"&RightTriangleEqual;":              true,
+	"&RightUpDownVector;":               true,
+	"&RightUpTeeVector;":                true,
+	"&RightUpVector;":                   true,
+	"&RightUpVectorBar;":                true,
+	"&RightVector;":                     true,
+	"&RightVectorBar;":                  true,
+	"&Rightarrow;":                      true,
+	"&Ropf;":                            true,
+	"&RoundImplies;":                    true,
+	"&Rrightarrow;":                     true,
+	"&Rscr;":                            true,
+	"&Rsh;":                             true,
+	"&RuleDelayed;":                     true,
+	"&SHCHcy;":                          true,
+	"&SHcy;":                            true,
+	"&SOFTcy;":                          true,
+	"&Sacute;":                          true,
+	"&Sc;":                              true,
+	"&Scaron;":                          true,
+	"&Scedil;":                          true,
+	"&Scirc;":                           true,
+	"&Scy;":                             true,
+	"&Sfr;":                             true,
+	"&ShortDownArrow;":                  true,
+	"&ShortLeftArrow;":                  true,
+	"&ShortRightArrow;":                 true,
+	"&ShortUpArrow;":                    true,
+	"&Sigma;":                           true,
+	"&SmallCircle;":                     true,
+	"&Sopf;":                            true,
+	"&Sqrt;":                            true,
+	"&Square;":                          true,
+	"&SquareIntersection;":              true,
+	"&SquareSubset;":                    true,
+	"&SquareSubsetEqual;":               true,
+	"&SquareSuperset;":                  true,
+	"&SquareSupersetEqual;":             true,
+	"&SquareUnion;":                     true,
+	"&Sscr;":                            true,
+	"&Star;":                            true,
+	"&Sub;":                             true,
+	"&Subset;":                          true,
+	"&SubsetEqual;":                     true,
+	"&Succeeds;":                        true,
+	"&SucceedsEqual;":                   true,
+	"&SucceedsSlantEqual;":              true,
+	"&SucceedsTilde;":                   true,
+	"&SuchThat;":                        true,
+	"&Sum;":                             true,
+	"&Sup;":                             true,
+	"&Superset;":                        true,
+	"&SupersetEqual;":                   true,
+	"&Supset;":                          true,
+	"&THORN":                            true,
+	"&THORN;":                           true,
+	"&TRADE;":                           true,
+	"&TSHcy;":                           true,
+	"&TScy;":                            true,
+	"&Tab;":                             true,
+	"&Tau;":                             true,
+	"&Tcaron;":                          true,
+	"&Tcedil;":                          true,
+	"&Tcy;":                             true,
+	"&Tfr;":                             true,
+	"&Therefore;":                       true,
+	"&Theta;":                           true,
+	"&ThickSpace;":                      true,
+	"&ThinSpace;":                       true,
+	"&Tilde;":                           true,
+	"&TildeEqual;":                      true,
+	"&TildeFullEqual;":                  true,
+	"&TildeTilde;":                      true,
+	"&Topf;":                            true,
+	"&TripleDot;":                       true,
+	"&Tscr;":                            true,
+	"&Tstrok;":                          true,
+	"&Uacute":                           true,
+	"&Uacute;":                          true,
+	"&Uarr;":                            true,
+	"&Uarrocir;":                        true,
+	"&Ubrcy;":                           true,
+	"&Ubreve;":                          true,
+	"&Ucirc":                            true,
+	"&Ucirc;":                           true,
+	"&Ucy;":                             true,
+	"&Udblac;":                          true,
+	"&Ufr;":                             true,
+	"&Ugrave":                           true,
+	"&Ugrave;":                          true,
+	"&Umacr;":                           true,
+	"&UnderBar;":                        true,
+	"&UnderBrace;":                      true,
+	"&UnderBracket;":                    true,
+	"&UnderParenthesis;":                true,
+	"&Union;":                           true,
+	"&UnionPlus;":                       true,
+	"&Uogon;":                           true,
+	"&Uopf;":                            true,
+	"&UpArrow;":                         true,
+	"&UpArrowBar;":                      true,
+	"&UpArrowDownArrow;":                true,
+	"&UpDownArrow;":                     true,
+	"&UpEquilibrium;":                   true,
+	"&UpTee;":                           true,
+	"&UpTeeArrow;":                      true,
+	"&Uparrow;":                         true,
+	"&Updownarrow;":                     true,
+	"&UpperLeftArrow;":                  true,
+	"&UpperRightArrow;":                 true,
+	"&Upsi;":                            true,
+	"&Upsilon;":                         true,
+	"&Uring;":                           true,
+	"&Uscr;":                            true,
+	"&Utilde;":                          true,
+	"&Uuml":                             true,
+	"&Uuml;":                            true,
+	"&VDash;":                           true,
+	"&Vbar;":                            true,
+	"&Vcy;":                             true,
+	"&Vdash;":                           true,
+	"&Vdashl;":                          true,
+	"&Vee;":                             true,
+	"&Verbar;":                          true,
+	"&Vert;":                            true,
+	"&VerticalBar;":                     true,
+	"&VerticalLine;":                    true,
+	"&VerticalSeparator;":               true,
+	"&VerticalTilde;":                   true,
+	"&VeryThinSpace;":                   true,
+	"&Vfr;":                             true,
+	"&Vopf;":                            true,
+	"&Vscr;":                            true,
+	"&Vvdash;":                          true,
+	"&Wcirc;":                           true,
+	"&Wedge;":                           true,
+	"&Wfr;":                             true,
+	"&Wopf;":                            true,
+	"&Wscr;":                            true,
+	"&Xfr;":                             true,
+	"&Xi;":                              true,
+	"&Xopf;":                            true,
+	"&Xscr;":                            true,
+	"&YAcy;":                            true,
+	"&YIcy;":                            true,
+	"&YUcy;":                            true,
+	"&Yacute":                           true,
+	"&Yacute;":                          true,
+	"&Ycirc;":                           true,
+	"&Ycy;":                             true,
+	"&Yfr;":                             true,
+	"&Yopf;":                            true,
+	"&Yscr;":                            true,
+	"&Yuml;":                            true,
+	"&ZHcy;":                            true,
+	"&Zacute;":                          true,
+	"&Zcaron;":                          true,
+	"&Zcy;":                             true,
+	"&Zdot;":                            true,
+	"&ZeroWidthSpace;":                  true,
+	"&Zeta;":                            true,
+	"&Zfr;":                             true,
+	"&Zopf;":                            true,
+	"&Zscr;":                            true,
+	"&aacute":                           true,
+	"&aacute;":                          true,
+	"&abreve;":                          true,
+	"&ac;":                              true,
+	"&acE;":                             true,
+	"&acd;":                             true,
+	"&acirc":                            true,
+	"&acirc;":                           true,
+	"&acute":                            true,
+	"&acute;":                           true,
+	"&acy;":                             true,
+	"&aelig":                            true,
+	"&aelig;":                           true,
+	"&af;":                              true,
+	"&afr;":                             true,
+	"&agrave":                           true,
+	"&agrave;":                          true,
+	"&alefsym;":                         true,
+	"&aleph;":                           true,
+	"&alpha;":                           true,
+	"&amacr;":                           true,
+	"&amalg;":                           true,
+	"&amp":                              true,
+	"&amp;":                             true,
+	"&and;":                             true,
+	"&andand;":                          true,
+	"&andd;":                            true,
+	"&andslope;":                        true,
+	"&andv;":                            true,
+	"&ang;":                             true,
+	"&ange;":                            true,
+	"&angle;":                           true,
+	"&angmsd;":                          true,
+	"&angmsdaa;":                        true,
+	"&angmsdab;":                        true,
+	"&angmsdac;":                        true,
+	"&angmsdad;":                        true,
+	"&angmsdae;":                        true,
+	"&angmsdaf;":                        true,
+	"&angmsdag;":                        true,
+	"&angmsdah;":                        true,
+	"&angrt;":                           true,
+	"&angrtvb;":                         true,
+	"&angrtvbd;":                        true,
+	"&angsph;":                          true,
+	"&angst;":                           true,
+	"&angzarr;":                         true,
+	"&aogon;":                           true,
+	"&aopf;":                            true,
+	"&ap;":                              true,
+	"&apE;":                             true,
+	"&apacir;":                          true,
+	"&ape;":                             true,
+	"&apid;":                            true,
+	"&apos;":                            true,
+	"&approx;":                          true,
+	"&approxeq;":                        true,
+	"&aring":                            true,
+	"&aring;":                           true,
+	"&ascr;":                            true,
+	"&ast;":                             true,
+	"&asymp;":                           true,
+	"&asympeq;":                         true,
+	"&atilde":                           true,
+	"&atilde;":                          true,
+	"&auml":                             true,
+	"&auml;":                            true,
+	"&awconint;":                        true,
+	"&awint;":                           true,
+	"&bNot;":                            true,
+	"&backcong;":                        true,
+	"&backepsilon;":                     true,
+	"&backprime;":                       true,
+	"&backsim;":                         true,
+	"&backsimeq;":                       true,
+	"&barvee;":                          true,
+	"&barwed;":                          true,
+	"&barwedge;":                        true,
+	"&bbrk;":                            true,
+	"&bbrktbrk;":                        true,
+	"&bcong;":                           true,
+	"&bcy;":                             true,
+	"&bdquo;":                           true,
+	"&becaus;":                          true,
+	"&because;":                         true,
+	"&bemptyv;":                         true,
+	"&bepsi;":                           true,
+	"&bernou;":                          true,
+	"&beta;":                            true,
+	"&beth;":                            true,
+	"&between;":                         true,
+	"&bfr;":                             true,
+	"&bigcap;":                          true,
+	"&bigcirc;":                         true,
+	"&bigcup;":                          true,
+	"&bigodot;":                         true,
+	"&bigoplus;":                        true,
+	"&bigotimes;":                       true,
+	"&bigsqcup;":                        true,
+	"&bigstar;":                         true,
+	"&bigtriangledown;":                 true,
+	"&bigtriangleup;":                   true,
+	"&biguplus;":                        true,
+	"&bigvee;":                          true,
+	"&bigwedge;":                        true,
+	"&bkarow;":                          true,
+	"&blacklozenge;":                    true,
+	"&blacksquare;":                     true,
+	"&blacktriangle;":                   true,
+	"&blacktriangledown;":               true,
+	"&blacktriangleleft;":               true,
+	"&blacktriangleright;":              true,
+	"&blank;":                           true,
+	"&blk12;":                           true,
+	"&blk14;":                           true,
+	"&blk34;":                           true,
+	"&block;":                           true,
+	"&bne;":                             true,
+	"&bnequiv;":                         true,
+	"&bnot;":                            true,
+	"&bopf;":                            true,
+	"&bot;":                             true,
+	"&bottom;":                          true,
+	"&bowtie;":                          true,
+	"&boxDL;":                           true,
+	"&boxDR;":                           true,
+	"&boxDl;":                           true,
+	"&boxDr;":                           true,
+	"&boxH;":                            true,
+	"&boxHD;":                           true,
+	"&boxHU;":                           true,
+	"&boxHd;":                           true,
+	"&boxHu;":                           true,
+	"&boxUL;":                           true,
+	"&boxUR;":                           true,
+	"&boxUl;":                           true,
+	"&boxUr;":                           true,
+	"&boxV;":                            true,
+	"&boxVH;":                           true,
+	"&boxVL;":                           true,
+	"&boxVR;":                           true,
+	"&boxVh;":                           true,
+	"&boxVl;":                           true,
+	"&boxVr;":                           true,
+	"&boxbox;":                          true,
+	"&boxdL;":                           true,
+	"&boxdR;":                           true,
+	"&boxdl;":                           true,
+	"&boxdr;":                           true,
+	"&boxh;":                            true,
+	"&boxhD;":                           true,
+	"&boxhU;":                           true,
+	"&boxhd;":                           true,
+	"&boxhu;":                           true,
+	"&boxminus;":                        true,
+	"&boxplus;":                         true,
+	"&boxtimes;":                        true,
+	"&boxuL;":                           true,
+	"&boxuR;":                           true,
+	"&boxul;":                           true,
+	"&boxur;":                           true,
+	"&boxv;":                            true,
+	"&boxvH;":                           true,
+	"&boxvL;":                           true,
+	"&boxvR;":                           true,
+	"&boxvh;":                           true,
+	"&boxvl;":                           true,
+	"&boxvr;":                           true,
+	"&bprime;":                          true,
+	"&breve;":                           true,
+	"&brvbar":                           true,
+	"&brvbar;":                          true,
+	"&bscr;":                            true,
+	"&bsemi;":                           true,
+	"&bsim;":                            true,
+	"&bsime;":                           true,
+	"&bsol;":                            true,
+	"&bsolb;":                           true,
+	"&bsolhsub;":                        true,
+	"&bull;":                            true,
+	"&bullet;":                          true,
+	"&bump;":                            true,
+	"&bumpE;":                           true,
+	"&bumpe;":                           true,
+	"&bumpeq;":                          true,
+	"&cacute;":                          true,
+	"&cap;":                             true,
+	"&capand;":                          true,
+	"&capbrcup;":                        true,
+	"&capcap;":                          true,
+	"&capcup;":                          true,
+	"&capdot;":                          true,
+	"&caps;":                            true,
+	"&caret;":                           true,
+	"&caron;":                           true,
+	"&ccaps;":                           true,
+	"&ccaron;":                          true,
+	"&ccedil":                           true,
+	"&ccedil;":                          true,
+	"&ccirc;":                           true,
+	"&ccups;":                           true,
+	"&ccupssm;":                         true,
+	"&cdot;":                            true,
+	"&cedil":                            true,
+	"&cedil;":                           true,
+	"&cemptyv;":                         true,
+	"&cent":                             true,
+	"&cent;":                            true,
+	"&centerdot;":                       true,
+	"&cfr;":                             true,
+	"&chcy;":                            true,
+	"&check;":                           true,
+	"&checkmark;":                       true,
+	"&chi;":                             true,
+	"&cir;":                             true,
+	"&cirE;":                            true,
+	"&circ;":                            true,
+	"&circeq;":                          true,
+	"&circlearrowleft;":                 true,
+	"&circlearrowright;":                true,
+	"&circledR;":                        true,
+	"&circledS;":                        true,
+	"&circledast;":                      true,
+	"&circledcirc;":                     true,
+	"&circleddash;":                     true,
+	"&cire;":                            true,
+	"&cirfnint;":                        true,
+	"&cirmid;":                          true,
+	"&cirscir;":                         true,
+	"&clubs;":                           true,
+	"&clubsuit;":                        true,
+	"&colon;":                           true,
+	"&colone;":                          true,
+	"&coloneq;":                         true,
+	"&comma;":                           true,
+	"&commat;":                          true,
+	"&comp;":                            true,
+	"&compfn;":                          true,
+	"&complement;":                      true,
+	"&complexes;":                       true,
+	"&cong;":                            true,
+	"&congdot;":                         true,
+	"&conint;":                          true,
+	"&copf;":                            true,
+	"&coprod;":                          true,
+	"&copy":                             true,
+	"&copy;":                            true,
+	"&copysr;":                          true,
+	"&crarr;":                           true,
+	"&cross;":                           true,
+	"&cscr;":                            true,
+	"&csub;":                            true,
+	"&csube;":                           true,
+	"&csup;":                            true,
+	"&csupe;":                           true,
+	"&ctdot;":                           true,
+	"&cudarrl;":                         true,
+	"&cudarrr;":                         true,
+	"&cuepr;":                           true,
+	"&cuesc;":                           true,
+	"&cularr;":                          true,
+	"&cularrp;":                         true,
+	"&cup;":                             true,
+	"&cupbrcap;":                        true,
+	"&cupcap;":                          true,
+	"&cupcup;":                          true,
+	"&cupdot;":                          true,
+	"&cupor;":                           true,
+	"&cups;":                            true,
+	"&curarr;":                          true,
+	"&curarrm;":                         true,
+	"&curlyeqprec;":                     true,
+	"&curlyeqsucc;":                     true,
+	"&curlyvee;":                        true,
+	"&curlywedge;":                      true,
+	"&curren":                           true,
+	"&curren;":                          true,
+	"&curvearrowleft;":                  true,
+	"&curvearrowright;":                 true,
+	"&cuvee;":                           true,
+	"&cuwed;":                           true,
+	"&cwconint;":                        true,
+	"&cwint;":                           true,
+	"&cylcty;":                          true,
+	"&dArr;":                            true,
+	"&dHar;":                            true,
+	"&dagger;":                          true,
+	"&daleth;":                          true,
+	"&darr;":                            true,
+	"&dash;":                            true,
+	"&dashv;":                           true,
+	"&dbkarow;":                         true,
+	"&dblac;":                           true,
+	"&dcaron;":                          true,
+	"&dcy;":                             true,
+	"&dd;":                              true,
+	"&ddagger;":                         true,
+	"&ddarr;":                           true,
+	"&ddotseq;":                         true,
+	"&deg":                              true,
+	"&deg;":                             true,
+	"&delta;":                           true,
+	"&demptyv;":                         true,
+	"&dfisht;":                          true,
+	"&dfr;":                             true,
+	"&dharl;":                           true,
+	"&dharr;":                           true,
+	"&diam;":                            true,
+	"&diamond;":                         true,
+	"&diamondsuit;":                     true,
+	"&diams;":                           true,
+	"&die;":                             true,
+	"&digamma;":                         true,
+	"&disin;":                           true,
+	"&div;":                             true,
+	"&divide":                           true,
+	"&divide;":                          true,
+	"&divideontimes;":                   true,
+	"&divonx;":                          true,
+	"&djcy;":                            true,
+	"&dlcorn;":                          true,
+	"&dlcrop;":                          true,
+	"&dollar;":                          true,
+	"&dopf;":                            true,
+	"&dot;":                             true,
+	"&doteq;":                           true,
+	"&doteqdot;":                        true,
+	"&dotminus;":                        true,
+	"&dotplus;":                         true,
+	"&dotsquare;":                       true,
+	"&doublebarwedge;":                  true,
+	"&downarrow;":                       true,
+	"&downdownarrows;":                  true,
+	"&downharpoonleft;":                 true,
+	"&downharpoonright;":                true,
+	"&drbkarow;":                        true,
+	"&drcorn;":                          true,
+	"&drcrop;":                          true,
+	"&dscr;":                            true,
+	"&dscy;":                            true,
+	"&dsol;":                            true,
+	"&dstrok;":                          true,
+	"&dtdot;":                           true,
+	"&dtri;":                            true,
+	"&dtrif;":                           true,
+	"&duarr;":                           true,
+	"&duhar;":                           true,
+	"&dwangle;":                         true,
+	"&dzcy;":                            true,
+	"&dzigrarr;":                        true,
+	"&eDDot;":                           true,
+	"&eDot;":                            true,
+	"&eacute":                           true,
+	"&eacute;":                          true,
+	"&easter;":                          true,
+	"&ecaron;":                          true,
+	"&ecir;":                            true,
+	"&ecirc":                            true,
+	"&ecirc;":                           true,
+	"&ecolon;":                          true,
+	"&ecy;":                             true,
+	"&edot;":                            true,
+	"&ee;":                              true,
+	"&efDot;":                           true,
+	"&efr;":                             true,
+	"&eg;":                              true,
+	"&egrave":                           true,
+	"&egrave;":                          true,
+	"&egs;":                             true,
+	"&egsdot;":                          true,
+	"&el;":                              true,
+	"&elinters;":                        true,
+	"&ell;":                             true,
+	"&els;":                             true,
+	"&elsdot;":                          true,
+	"&emacr;":                           true,
+	"&empty;":                           true,
+	"&emptyset;":                        true,
+	"&emptyv;":                          true,
+	"&emsp13;":                          true,
+	"&emsp14;":                          true,
+	"&emsp;":                            true,
+	"&eng;":                             true,
+	"&ensp;":                            true,
+	"&eogon;":                           true,
+	"&eopf;":                            true,
+	"&epar;":                            true,
+	"&eparsl;":                          true,
+	"&eplus;":                           true,
+	"&epsi;":                            true,
+	"&epsilon;":                         true,
+	"&epsiv;":                           true,
+	"&eqcirc;":                          true,
+	"&eqcolon;":                         true,
+	"&eqsim;":                           true,
+	"&eqslantgtr;":                      true,
+	"&eqslantless;":                     true,
+	"&equals;":                          true,
+	"&equest;":                          true,
+	"&equiv;":                           true,
+	"&equivDD;":                         true,
+	"&eqvparsl;":                        true,
+	"&erDot;":                           true,
+	"&erarr;":                           true,
+	"&escr;":                            true,
+	"&esdot;":                           true,
+	"&esim;":                            true,
+	"&eta;":                             true,
+	"&eth":                              true,
+	"&eth;":                             true,
+	"&euml":                             true,
+	"&euml;":                            true,
+	"&euro;":                            true,
+	"&excl;":                            true,
+	"&exist;":                           true,
+	"&expectation;":                     true,
+	"&exponentiale;":                    true,
+	"&fallingdotseq;":                   true,
+	"&fcy;":                             true,
+	"&female;":                          true,
+	"&ffilig;":                          true,
+	"&fflig;":                           true,
+	"&ffllig;":                          true,
+	"&ffr;":                             true,
+	"&filig;":                           true,
+	"&fjlig;":                           true,
+	"&flat;":                            true,
+	"&fllig;":                           true,
+	"&fltns;":                           true,
+	"&fnof;":                            true,
+	"&fopf;":                            true,
+	"&forall;":                          true,
+	"&fork;":                            true,
+	"&forkv;":                           true,
+	"&fpartint;":                        true,
+	"&frac12":                           true,
+	"&frac12;":                          true,
+	"&frac13;":                          true,
+	"&frac14":                           true,
+	"&frac14;":                          true,
+	"&frac15;":                          true,
+	"&frac16;":                          true,
+	"&frac18;":                          true,
+	"&frac23;":                          true,
+	"&frac25;":                          true,
+	"&frac34":                           true,
+	"&frac34;":                          true,
+	"&frac35;":                          true,
+	"&frac38;":                          true,
+	"&frac45;":                          true,
+	"&frac56;":                          true,
+	"&frac58;":                          true,
+	"&frac78;":                          true,
+	"&frasl;":                           true,
+	"&frown;":                           true,
+	"&fscr;":                            true,
+	"&gE;":                              true,
+	"&gEl;":                             true,
+	"&gacute;":                          true,
+	"&gamma;":                           true,
+	"&gammad;":                          true,
+	"&gap;":                             true,
+	"&gbreve;":                          true,
+	"&gcirc;":                           true,
+	"&gcy;":                             true,
+	"&gdot;":                            true,
+	"&ge;":                              true,
+	"&gel;":                             true,
+	"&geq;":                             true,
+	"&geqq;":                            true,
+	"&geqslant;":                        true,
+	"&ges;":                             true,
+	"&gescc;":                           true,
+	"&gesdot;":                          true,
+	"&gesdoto;":                         true,
+	"&gesdotol;":                        true,
+	"&gesl;":                            true,
+	"&gesles;":                          true,
+	"&gfr;":                             true,
+	"&gg;":                              true,
+	"&ggg;":                             true,
+	"&gimel;":                           true,
+	"&gjcy;":                            true,
+	"&gl;":                              true,
+	"&glE;":                             true,
+	"&gla;":                             true,
+	"&glj;":                             true,
+	"&gnE;":                             true,
+	"&gnap;":                            true,
+	"&gnapprox;":                        true,
+	"&gne;":                             true,
+	"&gneq;":                            true,
+	"&gneqq;":                           true,
+	"&gnsim;":                           true,
+	"&gopf;":                            true,
+	"&grave;":                           true,
+	"&gscr;":                            true,
+	"&gsim;":                            true,
+	"&gsime;":                           true,
+	"&gsiml;":                           true,
+	"&gt":                               true,
+	"&gt;":                              true,
+	"&gtcc;":                            true,
+	"&gtcir;":                           true,
+	"&gtdot;":                           true,
+	"&gtlPar;":                          true,
+	"&gtquest;":                         true,
+	"&gtrapprox;":                       true,
+	"&gtrarr;":                          true,
+	"&gtrdot;":                          true,
+	"&gtreqless;":                       true,
+	"&gtreqqless;":                      true,
+	"&gtrless;":                         true,
+	"&gtrsim;":                          true,
+	"&gvertneqq;":                       true,
+	"&gvnE;":                            true,
+	"&hArr;":                            true,
+	"&hairsp;":                          true,
+	"&half;":                            true,
+	"&hamilt;":                          true,
+	"&hardcy;":                          true,
+	"&harr;":                            true,
+	"&harrcir;":                         true,
+	"&harrw;":                           true,
+	"&hbar;":                            true,
+	"&hcirc;":                           true,
+	"&hearts;":                          true,
+	"&heartsuit;":                       true,
+	"&hellip;":                          true,
+	"&hercon;":                          true,
+	"&hfr;":                             true,
+	"&hksearow;":                        true,
+	"&hkswarow;":                        true,
+	"&hoarr;":                           true,
+	"&homtht;":                          true,
+	"&hookleftarrow;":                   true,
+	"&hookrightarrow;":                  true,
+	"&hopf;":                            true,
+	"&horbar;":                          true,
+	"&hscr;":                            true,
+	"&hslash;":                          true,
+	"&hstrok;":                          true,
+	"&hybull;":                          true,
+	"&hyphen;":                          true,
+	"&iacute":                           true,
+	"&iacute;":                          true,
+	"&ic;":                              true,
+	"&icirc":                            true,
+	"&icirc;":                           true,
+	"&icy;":                             true,
+	"&iecy;":                            true,
+	"&iexcl":                            true,
+	"&iexcl;":                           true,
+	"&iff;":                             true,
+	"&ifr;":                             true,
+	"&igrave":                           true,
+	"&igrave;":                          true,
+	"&ii;":                              true,
+	"&iiiint;":                          true,
+	"&iiint;":                           true,
+	"&iinfin;":                          true,
+	"&iiota;":                           true,
+	"&ijlig;":                           true,
+	"&imacr;":                           true,
+	"&image;":                           true,
+	"&imagline;":                        true,
+	"&imagpart;":                        true,
+	"&imath;":                           true,
+	"&imof;":                            true,
+	"&imped;":                           true,
+	"&in;":                              true,
+	"&incare;":                          true,
+	"&infin;":                           true,
+	"&infintie;":                        true,
+	"&inodot;":                          true,
+	"&int;":                             true,
+	"&intcal;":                          true,
+	"&integers;":                        true,
+	"&intercal;":                        true,
+	"&intlarhk;":                        true,
+	"&intprod;":                         true,
+	"&iocy;":                            true,
+	"&iogon;":                           true,
+	"&iopf;":                            true,
+	"&iota;":                            true,
+	"&iprod;":                           true,
+	"&iquest":                           true,
+	"&iquest;":                          true,
+	"&iscr;":                            true,
+	"&isin;":                            true,
+	"&isinE;":                           true,
+	"&isindot;":                         true,
+	"&isins;":                           true,
+	"&isinsv;":                          true,
+	"&isinv;":                           true,
+	"&it;":                              true,
+	"&itilde;":                          true,
+	"&iukcy;":                           true,
+	"&iuml":                             true,
+	"&iuml;":                            true,
+	"&jcirc;":                           true,
+	"&jcy;":                             true,
+	"&jfr;":                             true,
+	"&jmath;":                           true,
+	"&jopf;":                            true,
+	"&jscr;":                            true,
+	"&jsercy;":                          true,
+	"&jukcy;":                           true,
+	"&kappa;":                           true,
+	"&kappav;":                          true,
+	"&kcedil;":                          true,
+	"&kcy;":                             true,
+	"&kfr;":                             true,
+	"&kgreen;":                          true,
+	"&khcy;":                            true,
+	"&kjcy;":                            true,
+	"&kopf;":                            true,
+	"&kscr;":                            true,
+	"&lAarr;":                           true,
+	"&lArr;":                            true,
+	"&lAtail;":                          true,
+	"&lBarr;":                           true,
+	"&lE;":                              true,
+	"&lEg;":                             true,
+	"&lHar;":                            true,
+	"&lacute;":                          true,
+	"&laemptyv;":                        true,
+	"&lagran;":                          true,
+	"&lambda;":                          true,
+	"&lang;":                            true,
+	"&langd;":                           true,
+	"&langle;":                          true,
+	"&lap;":                             true,
+	"&laquo":                            true,
+	"&laquo;":                           true,
+	"&larr;":                            true,
+	"&larrb;":                           true,
+	"&larrbfs;":                         true,
+	"&larrfs;":                          true,
+	"&larrhk;":                          true,
+	"&larrlp;":                          true,
+	"&larrpl;":                          true,
+	"&larrsim;":                         true,
+	"&larrtl;":                          true,
+	"&lat;":                             true,
+	"&latail;":                          true,
+	"&late;":                            true,
+	"&lates;":                           true,
+	"&lbarr;":                           true,
+	"&lbbrk;":                           true,
+	"&lbrace;":                          true,
+	"&lbrack;":                          true,
+	"&lbrke;":                           true,
+	"&lbrksld;":                         true,
+	"&lbrkslu;":                         true,
+	"&lcaron;":                          true,
+	"&lcedil;":                          true,
+	"&lceil;":                           true,
+	"&lcub;":                            true,
+	"&lcy;":                             true,
+	"&ldca;":                            true,
+	"&ldquo;":                           true,
+	"&ldquor;":                          true,
+	"&ldrdhar;":                         true,
+	"&ldrushar;":                        true,
+	"&ldsh;":                            true,
+	"&le;":                              true,
+	"&leftarrow;":                       true,
+	"&leftarrowtail;":                   true,
+	"&leftharpoondown;":                 true,
+	"&leftharpoonup;":                   true,
+	"&leftleftarrows;":                  true,
+	"&leftrightarrow;":                  true,
+	"&leftrightarrows;":                 true,
+	"&leftrightharpoons;":               true,
+	"&leftrightsquigarrow;":             true,
+	"&leftthreetimes;":                  true,
+	"&leg;":                             true,
+	"&leq;":                             true,
+	"&leqq;":                            true,
+	"&leqslant;":                        true,
+	"&les;":                             true,
+	"&lescc;":                           true,
+	"&lesdot;":                          true,
+	"&lesdoto;":                         true,
+	"&lesdotor;":                        true,
+	"&lesg;":                            true,
+	"&lesges;":                          true,
+	"&lessapprox;":                      true,
+	"&lessdot;":                         true,
+	"&lesseqgtr;":                       true,
+	"&lesseqqgtr;":                      true,
+	"&lessgtr;":                         true,
+	"&lesssim;":                         true,
+	"&lfisht;":                          true,
+	"&lfloor;":                          true,
+	"&lfr;":                             true,
+	"&lg;":                              true,
+	"&lgE;":                             true,
+	"&lhard;":                           true,
+	"&lharu;":                           true,
+	"&lharul;":                          true,
+	"&lhblk;":                           true,
+	"&ljcy;":                            true,
+	"&ll;":                              true,
+	"&llarr;":                           true,
+	"&llcorner;":                        true,
+	"&llhard;":                          true,
+	"&lltri;":                           true,
+	"&lmidot;":                          true,
+	"&lmoust;":                          true,
+	"&lmoustache;":                      true,
+	"&lnE;":                             true,
+	"&lnap;":                            true,
+	"&lnapprox;":                        true,
+	"&lne;":                             true,
+	"&lneq;":                            true,
+	"&lneqq;":                           true,
+	"&lnsim;":                           true,
+	"&loang;":                           true,
+	"&loarr;":                           true,
+	"&lobrk;":                           true,
+	"&longleftarrow;":                   true,
+	"&longleftrightarrow;":              true,
+	"&longmapsto;":                      true,
+	"&longrightarrow;":                  true,
+	"&looparrowleft;":                   true,
+	"&looparrowright;":                  true,
+	"&lopar;":                           true,
+	"&lopf;":                            true,
+	"&loplus;":                          true,
+	"&lotimes;":                         true,
+	"&lowast;":                          true,
+	"&lowbar;":                          true,
+	"&loz;":                             true,
+	"&lozenge;":                         true,
+	"&lozf;":                            true,
+	"&lpar;":                            true,
+	"&lparlt;":                          true,
+	"&lrarr;":                           true,
+	"&lrcorner;":                        true,
+	"&lrhar;":                           true,
+	"&lrhard;":                          true,
+	"&lrm;":                             true,
+	"&lrtri;":                           true,
+	"&lsaquo;":                          true,
+	"&lscr;":                            true,
+	"&lsh;":                             true,
+	"&lsim;":                            true,
+	"&lsime;":                           true,
+	"&lsimg;":                           true,
+	"&lsqb;":                            true,
+	"&lsquo;":                           true,
+	"&lsquor;":                          true,
+	"&lstrok;":                          true,
+	"&lt":                               true,
+	"&lt;":                              true,
+	"&ltcc;":                            true,
+	"&ltcir;":                           true,
+	"&ltdot;":                           true,
+	"&lthree;":                          true,
+	"&ltimes;":                          true,
+	"&ltlarr;":                          true,
+	"&ltquest;":                         true,
+	"&ltrPar;":                          true,
+	"&ltri;":                            true,
+	"&ltrie;":                           true,
+	"&ltrif;":                           true,
+	"&lurdshar;":                        true,
+	"&luruhar;":                         true,
+	"&lvertneqq;":                       true,
+	"&lvnE;":                            true,
+	"&mDDot;":                           true,
+	"&macr":                             true,
+	"&macr;":                            true,
+	"&male;":                            true,
+	"&malt;":                            true,
+	"&maltese;":                         true,
+	"&map;":                             true,
+	"&mapsto;":                          true,
+	"&mapstodown;":                      true,
+	"&mapstoleft;":                      true,
+	"&mapstoup;":                        true,
+	"&marker;":                          true,
+	"&mcomma;":                          true,
+	"&mcy;":                             true,
+	"&mdash;":                           true,
+	"&measuredangle;":                   true,
+	"&mfr;":                             true,
+	"&mho;":                             true,
+	"&micro":                            true,
+	"&micro;":                           true,
+	"&mid;":                             true,
+	"&midast;":                          true,
+	"&midcir;":                          true,
+	"&middot":                           true,
+	"&middot;":                          true,
+	"&minus;":                           true,
+	"&minusb;":                          true,
+	"&minusd;":                          true,
+	"&minusdu;":                         true,
+	"&mlcp;":                            true,
+	"&mldr;":                            true,
+	"&mnplus;":                          true,
+	"&models;":                          true,
+	"&mopf;":                            true,
+	"&mp;":                              true,
+	"&mscr;":                            true,
+	"&mstpos;":                          true,
+	"&mu;":                              true,
+	"&multimap;":                        true,
+	"&mumap;":                           true,
+	"&nGg;":                             true,
+	"&nGt;":                             true,
+	"&nGtv;":                            true,
+	"&nLeftarrow;":                      true,
+	"&nLeftrightarrow;":                 true,
+	"&nLl;":                             true,
+	"&nLt;":                             true,
+	"&nLtv;":                            true,
+	"&nRightarrow;":                     true,
+	"&nVDash;":                          true,
+	"&nVdash;":                          true,
+	"&nabla;":                           true,
+	"&nacute;":                          true,
+	"&nang;":                            true,
+	"&nap;":                             true,
+	"&napE;":                            true,
+	"&napid;":                           true,
+	"&napos;":                           true,
+	"&napprox;":                         true,
+	"&natur;":                           true,
+	"&natural;":                         true,
+	"&naturals;":                        true,
+	"&nbsp":                             true,
+	"&nbsp;":                            true,
+	"&nbump;":                           true,
+	"&nbumpe;":                          true,
+	"&ncap;":                            true,
+	"&ncaron;":                          true,
+	"&ncedil;":                          true,
+	"&ncong;":                           true,
+	"&ncongdot;":                        true,
+	"&ncup;":                            true,
+	"&ncy;":                             true,
+	"&ndash;":                           true,
+	"&ne;":                              true,
+	"&neArr;":                           true,
+	"&nearhk;":                          true,
+	"&nearr;":                           true,
+	"&nearrow;":                         true,
+	"&nedot;":                           true,
+	"&nequiv;":                          true,
+	"&nesear;":                          true,
+	"&nesim;":                           true,
+	"&nexist;":                          true,
+	"&nexists;":                         true,
+	"&nfr;":                             true,
+	"&ngE;":                             true,
+	"&nge;":                             true,
+	"&ngeq;":                            true,
+	"&ngeqq;":                           true,
+	"&ngeqslant;":                       true,
+	"&nges;":                            true,
+	"&ngsim;":                           true,
+	"&ngt;":                             true,
+	"&ngtr;":                            true,
+	"&nhArr;":                           true,
+	"&nharr;":                           true,
+	"&nhpar;":                           true,
+	"&ni;":                              true,
+	"&nis;":                             true,
+	"&nisd;":                            true,
+	"&niv;":                             true,
+	"&njcy;":                            true,
+	"&nlArr;":                           true,
+	"&nlE;":                             true,
+	"&nlarr;":                           true,
+	"&nldr;":                            true,
+	"&nle;":                             true,
+	"&nleftarrow;":                      true,
+	"&nleftrightarrow;":                 true,
+	"&nleq;":                            true,
+	"&nleqq;":                           true,
+	"&nleqslant;":                       true,
+	"&nles;":                            true,
+	"&nless;":                           true,
+	"&nlsim;":                           true,
+	"&nlt;":                             true,
+	"&nltri;":                           true,
+	"&nltrie;":                          true,
+	"&nmid;":                            true,
+	"&nopf;":                            true,
+	"&not":                              true,
+	"&not;":                             true,
+	"&notin;":                           true,
+	"&notinE;":                          true,
+	"&notindot;":                        true,
+	"&notinva;":                         true,
+	"&notinvb;":                         true,
+	"&notinvc;":                         true,
+	"&notni;":                           true,
+	"&notniva;":                         true,
+	"&notnivb;":                         true,
+	"&notnivc;":                         true,
+	"&npar;":                            true,
+	"&nparallel;":                       true,
+	"&nparsl;":                          true,
+	"&npart;":                           true,
+	"&npolint;":                         true,
+	"&npr;":                             true,
+	"&nprcue;":                          true,
+	"&npre;":                            true,
+	"&nprec;":                           true,
+	"&npreceq;":                         true,
+	"&nrArr;":                           true,
+	"&nrarr;":                           true,
+	"&nrarrc;":                          true,
+	"&nrarrw;":                          true,
+	"&nrightarrow;":                     true,
+	"&nrtri;":                           true,
+	"&nrtrie;":                          true,
+	"&nsc;":                             true,
+	"&nsccue;":                          true,
+	"&nsce;":                            true,
+	"&nscr;":                            true,
+	"&nshortmid;":                       true,
+	"&nshortparallel;":                  true,
+	"&nsim;":                            true,
+	"&nsime;":                           true,
+	"&nsimeq;":                          true,
+	"&nsmid;":                           true,
+	"&nspar;":                           true,
+	"&nsqsube;":                         true,
+	"&nsqsupe;":                         true,
+	"&nsub;":                            true,
+	"&nsubE;":                           true,
+	"&nsube;":                           true,
+	"&nsubset;":                         true,
+	"&nsubseteq;":                       true,
+	"&nsubseteqq;":                      true,
+	"&nsucc;":                           true,
+	"&nsucceq;":                         true,
+	"&nsup;":                            true,
+	"&nsupE;":                           true,
+	"&nsupe;":                           true,
+	"&nsupset;":                         true,
+	"&nsupseteq;":                       true,
+	"&nsupseteqq;":                      true,
+	"&ntgl;":                            true,
+	"&ntilde":                           true,
+	"&ntilde;":                          true,
+	"&ntlg;":                            true,
+	"&ntriangleleft;":                   true,
+	"&ntrianglelefteq;":                 true,
+	"&ntriangleright;":                  true,
+	"&ntrianglerighteq;":                true,
+	"&nu;":                              true,
+	"&num;":                             true,
+	"&numero;":                          true,
+	"&numsp;":                           true,
+	"&nvDash;":                          true,
+	"&nvHarr;":                          true,
+	"&nvap;":                            true,
+	"&nvdash;":                          true,
+	"&nvge;":                            true,
+	"&nvgt;":                            true,
+	"&nvinfin;":                         true,
+	"&nvlArr;":                          true,
+	"&nvle;":                            true,
+	"&nvlt;":                            true,
+	"&nvltrie;":                         true,
+	"&nvrArr;":                          true,
+	"&nvrtrie;":                         true,
+	"&nvsim;":                           true,
+	"&nwArr;":                           true,
+	"&nwarhk;":                          true,
+	"&nwarr;":                           true,
+	"&nwarrow;":                         true,
+	"&nwnear;":                          true,
+	"&oS;":                              true,
+	"&oacute":                           true,
+	"&oacute;":                          true,
+	"&oast;":                            true,
+	"&ocir;":                            true,
+	"&ocirc":                            true,
+	"&ocirc;":                           true,
+	"&ocy;":                             true,
+	"&odash;":                           true,
+	"&odblac;":                          true,
+	"&odiv;":                            true,
+	"&odot;":                            true,
+	"&odsold;":                          true,
+	"&oelig;":                           true,
+	"&ofcir;":                           true,
+	"&ofr;":                             true,
+	"&ogon;":                            true,
+	"&ograve":                           true,
+	"&ograve;":                          true,
+	"&ogt;":                             true,
+	"&ohbar;":                           true,
+	"&ohm;":                             true,
+	"&oint;":                            true,
+	"&olarr;":                           true,
+	"&olcir;":                           true,
+	"&olcross;":                         true,
+	"&oline;":                           true,
+	"&olt;":                             true,
+	"&omacr;":                           true,
+	"&omega;":                           true,
+	"&omicron;":                         true,
+	"&omid;":                            true,
+	"&ominus;":                          true,
+	"&oopf;":                            true,
+	"&opar;":                            true,
+	"&operp;":                           true,
+	"&oplus;":                           true,
+	"&or;":                              true,
+	"&orarr;":                           true,
+	"&ord;":                             true,
+	"&order;":                           true,
+	"&orderof;":                         true,
+	"&ordf":                             true,
+	"&ordf;":                            true,
+	"&ordm":                             true,
+	"&ordm;":                            true,
+	"&origof;":                          true,
+	"&oror;":                            true,
+	"&orslope;":                         true,
+	"&orv;":                             true,
+	"&oscr;":                            true,
+	"&oslash":                           true,
+	"&oslash;":                          true,
+	"&osol;":                            true,
+	"&otilde":                           true,
+	"&otilde;":                          true,
+	"&otimes;":                          true,
+	"&otimesas;":                        true,
+	"&ouml":                             true,
+	"&ouml;":                            true,
+	"&ovbar;":                           true,
+	"&par;":                             true,
+	"&para":                             true,
+	"&para;":                            true,
+	"&parallel;":                        true,
+	"&parsim;":                          true,
+	"&parsl;":                           true,
+	"&part;":                            true,
+	"&pcy;":                             true,
+	"&percnt;":                          true,
+	"&period;":                          true,
+	"&permil;":                          true,
+	"&perp;":                            true,
+	"&pertenk;":                         true,
+	"&pfr;":                             true,
+	"&phi;":                             true,
+	"&phiv;":                            true,
+	"&phmmat;":                          true,
+	"&phone;":                           true,
+	"&pi;":                              true,
+	"&pitchfork;":                       true,
+	"&piv;":                             true,
+	"&planck;":                          true,
+	"&planckh;":                         true,
+	"&plankv;":                          true,
+	"&plus;":                            true,
+	"&plusacir;":                        true,
+	"&plusb;":                           true,
+	"&pluscir;":                         true,
+	"&plusdo;":                          true,
+	"&plusdu;":                          true,
+	"&pluse;":                           true,
+	"&plusmn":                           true,
+	"&plusmn;":                          true,
+	"&plussim;":                         true,
+	"&plustwo;":                         true,
+	"&pm;":                              true,
+	"&pointint;":                        true,
+	"&popf;":                            true,
+	"&pound":                            true,
+	"&pound;":                           true,
+	"&pr;":                              true,
+	"&prE;":                             true,
+	"&prap;":                            true,
+	"&prcue;":                           true,
+	"&pre;":                             true,
+	"&prec;":                            true,
+	"&precapprox;":                      true,
+	"&preccurlyeq;":                     true,
+	"&preceq;":                          true,
+	"&precnapprox;":                     true,
+	"&precneqq;":                        true,
+	"&precnsim;":                        true,
+	"&precsim;":                         true,
+	"&prime;":                           true,
+	"&primes;":                          true,
+	"&prnE;":                            true,
+	"&prnap;":                           true,
+	"&prnsim;":                          true,
+	"&prod;":                            true,
+	"&profalar;":                        true,
+	"&profline;":                        true,
+	"&profsurf;":                        true,
+	"&prop;":                            true,
+	"&propto;":                          true,
+	"&prsim;":                           true,
+	"&prurel;":                          true,
+	"&pscr;":                            true,
+	"&psi;":                             true,
+	"&puncsp;":                          true,
+	"&qfr;":                             true,
+	"&qint;":                            true,
+	"&qopf;":                            true,
+	"&qprime;":                          true,
+	"&qscr;":                            true,
+	"&quaternions;":                     true,
+	"&quatint;":                         true,
+	"&quest;":                           true,
+	"&questeq;":                         true,
+	"&quot":                             true,
+	"&quot;":                            true,
+	"&rAarr;":                           true,
+	"&rArr;":                            true,
+	"&rAtail;":                          true,
+	"&rBarr;":                           true,
+	"&rHar;":                            true,
+	"&race;":                            true,
+	"&racute;":                          true,
+	"&radic;":                           true,
+	"&raemptyv;":                        true,
+	"&rang;":                            true,
+	"&rangd;":                           true,
+	"&range;":                           true,
+	"&rangle;":                          true,
+	"&raquo":                            true,
+	"&raquo;":                           true,
+	"&rarr;":                            true,
+	"&rarrap;":                          true,
+	"&rarrb;":                           true,
+	"&rarrbfs;":                         true,
+	"&rarrc;":                           true,
+	"&rarrfs;":                          true,
+	"&rarrhk;":                          true,
+	"&rarrlp;":                          true,
+	"&rarrpl;":                          true,
+	"&rarrsim;":                         true,
+	"&rarrtl;":                          true,
+	"&rarrw;":                           true,
+	"&ratail;":                          true,
+	"&ratio;":                           true,
+	"&rationals;":                       true,
+	"&rbarr;":                           true,
+	"&rbbrk;":                           true,
+	"&rbrace;":                          true,
+	"&rbrack;":                          true,
+	"&rbrke;":                           true,
+	"&rbrksld;":                         true,
+	"&rbrkslu;":                         true,
+	"&rcaron;":                          true,
+	"&rcedil;":                          true,
+	"&rceil;":                           true,
+	"&rcub;":                            true,
+	"&rcy;":                             true,
+	"&rdca;":                            true,
+	"&rdldhar;":                         true,
+	"&rdquo;":                           true,
+	"&rdquor;":                          true,
+	"&rdsh;":                            true,
+	"&real;":                            true,
+	"&realine;":                         true,
+	"&realpart;":                        true,
+	"&reals;":                           true,
+	"&rect;":                            true,
+	"&reg":                              true,
+	"&reg;":                             true,
+	"&rfisht;":                          true,
+	"&rfloor;":                          true,
+	"&rfr;":                             true,
+	"&rhard;":                           true,
+	"&rharu;":                           true,
+	"&rharul;":                          true,
+	"&rho;":                             true,
+	"&rhov;":                            true,
+	"&rightarrow;":                      true,
+	"&rightarrowtail;":                  true,
+	"&rightharpoondown;":                true,
+	"&rightharpoonup;":                  true,
+	"&rightleftarrows;":                 true,
+	"&rightleftharpoons;":               true,
+	"&rightrightarrows;":                true,
+	"&rightsquigarrow;":                 true,
+	"&rightthreetimes;":                 true,
+	"&ring;":                            true,
+	"&risingdotseq;":                    true,
+	"&rlarr;":                           true,
+	"&rlhar;":                           true,
+	"&rlm;":                             true,
+	"&rmoust;":                          true,
+	"&rmoustache;":                      true,
+	"&rnmid;":                           true,
+	"&roang;":                           true,
+	"&roarr;":                           true,
+	"&robrk;":                           true,
+	"&ropar;":                           true,
+	"&ropf;":                            true,
+	"&roplus;":                          true,
+	"&rotimes;":                         true,
+	"&rpar;":                            true,
+	"&rpargt;":                          true,
+	"&rppolint;":                        true,
+	"&rrarr;":                           true,
+	"&rsaquo;":                          true,
+	"&rscr;":                            true,
+	"&rsh;":                             true,
+	"&rsqb;":                            true,
+	"&rsquo;":                           true,
+	"&rsquor;":                          true,
+	"&rthree;":                          true,
+	"&rtimes;":                          true,
+	"&rtri;":                            true,
+	"&rtrie;":                           true,
+	"&rtrif;":                           true,
+	"&rtriltri;":                        true,
+	"&ruluhar;":                         true,
+	"&rx;":                              true,
+	"&sacute;":                          true,
+	"&sbquo;":                           true,
+	"&sc;":                              true,
+	"&scE;":                             true,
+	"&scap;":                            true,
+	"&scaron;":                          true,
+	"&sccue;":                           true,
+	"&sce;":                             true,
+	"&scedil;":                          true,
+	"&scirc;":                           true,
+	"&scnE;":                            true,
+	"&scnap;":                           true,
+	"&scnsim;":                          true,
+	"&scpolint;":                        true,
+	"&scsim;":                           true,
+	"&scy;":                             true,
+	"&sdot;":                            true,
+	"&sdotb;":                           true,
+	"&sdote;":                           true,
+	"&seArr;":                           true,
+	"&searhk;":                          true,
+	"&searr;":                           true,
+	"&searrow;":                         true,
+	"&sect":                             true,
+	"&sect;":                            true,
+	"&semi;":                            true,
+	"&seswar;":                          true,
+	"&setminus;":                        true,
+	"&setmn;":                           true,
+	"&sext;":                            true,
+	"&sfr;":                             true,
+	"&sfrown;":                          true,
+	"&sharp;":                           true,
+	"&shchcy;":                          true,
+	"&shcy;":                            true,
+	"&shortmid;":                        true,
+	"&shortparallel;":                   true,
+	"&shy":                              true,
+	"&shy;":                             true,
+	"&sigma;":                           true,
+	"&sigmaf;":                          true,
+	"&sigmav;":                          true,
+	"&sim;":                             true,
+	"&simdot;":                          true,
+	"&sime;":                            true,
+	"&simeq;":                           true,
+	"&simg;":                            true,
+	"&simgE;":                           true,
+	"&siml;":                            true,
+	"&simlE;":                           true,
+	"&simne;":                           true,
+	"&simplus;":                         true,
+	"&simrarr;":                         true,
+	"&slarr;":                           true,
+	"&smallsetminus;":                   true,
+	"&smashp;":                          true,
+	"&smeparsl;":                        true,
+	"&smid;":                            true,
+	"&smile;":                           true,
+	"&smt;":                             true,
+	"&smte;":                            true,
+	"&smtes;":                           true,
+	"&softcy;":                          true,
+	"&sol;":                             true,
+	"&solb;":                            true,
+	"&solbar;":                          true,
+	"&sopf;":                            true,
+	"&spades;":                          true,
+	"&spadesuit;":                       true,
+	"&spar;":                            true,
+	"&sqcap;":                           true,
+	"&sqcaps;":                          true,
+	"&sqcup;":                           true,
+	"&sqcups;":                          true,
+	"&sqsub;":                           true,
+	"&sqsube;":                          true,
+	"&sqsubset;":                        true,
+	"&sqsubseteq;":                      true,
+	"&sqsup;":                           true,
+	"&sqsupe;":                          true,
+	"&sqsupset;":                        true,
+	"&sqsupseteq;":                      true,
+	"&squ;":                             true,
+	"&square;":                          true,
+	"&squarf;":                          true,
+	"&squf;":                            true,
+	"&srarr;":                           true,
+	"&sscr;":                            true,
+	"&ssetmn;":                          true,
+	"&ssmile;":                          true,
+	"&sstarf;":                          true,
+	"&star;":                            true,
+	"&starf;":                           true,
+	"&straightepsilon;":                 true,
+	"&straightphi;":                     true,
+	"&strns;":                           true,
+	"&sub;":                             true,
+	"&subE;":                            true,
+	"&subdot;":                          true,
+	"&sube;":                            true,
+	"&subedot;":                         true,
+	"&submult;":                         true,
+	"&subnE;":                           true,
+	"&subne;":                           true,
+	"&subplus;":                         true,
+	"&subrarr;":                         true,
+	"&subset;":                          true,
+	"&subseteq;":                        true,
+	"&subseteqq;":                       true,
+	"&subsetneq;":                       true,
+	"&subsetneqq;":                      true,
+	"&subsim;":                          true,
+	"&subsub;":                          true,
+	"&subsup;":                          true,
+	"&succ;":                            true,
+	"&succapprox;":                      true,
+	"&succcurlyeq;":                     true,
+	"&succeq;":                          true,
+	"&succnapprox;":                     true,
+	"&succneqq;":                        true,
+	"&succnsim;":                        true,
+	"&succsim;":                         true,
+	"&sum;":                             true,
+	"&sung;":                            true,
+	"&sup1":                             true,
+	"&sup1;":                            true,
+	"&sup2":                             true,
+	"&sup2;":                            true,
+	"&sup3":                             true,
+	"&sup3;":                            true,
+	"&sup;":                             true,
+	"&supE;":                            true,
+	"&supdot;":                          true,
+	"&supdsub;":                         true,
+	"&supe;":                            true,
+	"&supedot;":                         true,
+	"&suphsol;":                         true,
+	"&suphsub;":                         true,
+	"&suplarr;":                         true,
+	"&supmult;":                         true,
+	"&supnE;":                           true,
+	"&supne;":                           true,
+	"&supplus;":                         true,
+	"&supset;":                          true,
+	"&supseteq;":                        true,
+	"&supseteqq;":                       true,
+	"&supsetneq;":                       true,
+	"&supsetneqq;":                      true,
+	"&supsim;":                          true,
+	"&supsub;":                          true,
+	"&supsup;":                          true,
+	"&swArr;":                           true,
+	"&swarhk;":                          true,
+	"&swarr;":                           true,
+	"&swarrow;":                         true,
+	"&swnwar;":                          true,
+	"&szlig":                            true,
+	"&szlig;":                           true,
+	"&target;":                          true,
+	"&tau;":                             true,
+	"&tbrk;":                            true,
+	"&tcaron;":                          true,
+	"&tcedil;":                          true,
+	"&tcy;":                             true,
+	"&tdot;":                            true,
+	"&telrec;":                          true,
+	"&tfr;":                             true,
+	"&there4;":                          true,
+	"&therefore;":                       true,
+	"&theta;":                           true,
+	"&thetasym;":                        true,
+	"&thetav;":                          true,
+	"&thickapprox;":                     true,
+	"&thicksim;":                        true,
+	"&thinsp;":                          true,
+	"&thkap;":                           true,
+	"&thksim;":                          true,
+	"&thorn":                            true,
+	"&thorn;":                           true,
+	"&tilde;":                           true,
+	"&times":                            true,
+	"&times;":                           true,
+	"&timesb;":                          true,
+	"&timesbar;":                        true,
+	"&timesd;":                          true,
+	"&tint;":                            true,
+	"&toea;":                            true,
+	"&top;":                             true,
+	"&topbot;":                          true,
+	"&topcir;":                          true,
+	"&topf;":                            true,
+	"&topfork;":                         true,
+	"&tosa;":                            true,
+	"&tprime;":                          true,
+	"&trade;":                           true,
+	"&triangle;":                        true,
+	"&triangledown;":                    true,
+	"&triangleleft;":                    true,
+	"&trianglelefteq;":                  true,
+	"&triangleq;":                       true,
+	"&triangleright;":                   true,
+	"&trianglerighteq;":                 true,
+	"&tridot;":                          true,
+	"&trie;":                            true,
+	"&triminus;":                        true,
+	"&triplus;":                         true,
+	"&trisb;":                           true,
+	"&tritime;":                         true,
+	"&trpezium;":                        true,
+	"&tscr;":                            true,
+	"&tscy;":                            true,
+	"&tshcy;":                           true,
+	"&tstrok;":                          true,
+	"&twixt;":                           true,
+	"&twoheadleftarrow;":                true,
+	"&twoheadrightarrow;":               true,
+	"&uArr;":                            true,
+	"&uHar;":                            true,
+	"&uacute":                           true,
+	"&uacute;":                          true,
+	"&uarr;":                            true,
+	"&ubrcy;":                           true,
+	"&ubreve;":                          true,
+	"&ucirc":                            true,
+	"&ucirc;":                           true,
+	"&ucy;":                             true,
+	"&udarr;":                           true,
+	"&udblac;":                          true,
+	"&udhar;":                           true,
+	"&ufisht;":                          true,
+	"&ufr;":                             true,
+	"&ugrave":                           true,
+	"&ugrave;":                          true,
+	"&uharl;":                           true,
+	"&uharr;":                           true,
+	"&uhblk;":                           true,
+	"&ulcorn;":                          true,
+	"&ulcorner;":                        true,
+	"&ulcrop;":                          true,
+	"&ultri;":                           true,
+	"&umacr;":                           true,
+	"&uml":                              true,
+	"&uml;":                             true,
+	"&uogon;":                           true,
+	"&uopf;":                            true,
+	"&uparrow;":                         true,
+	"&updownarrow;":                     true,
+	"&upharpoonleft;":                   true,
+	"&upharpoonright;":                  true,
+	"&uplus;":                           true,
+	"&upsi;":                            true,
+	"&upsih;":                           true,
+	"&upsilon;":                         true,
+	"&upuparrows;":                      true,
+	"&urcorn;":                          true,
+	"&urcorner;":                        true,
+	"&urcrop;":                          true,
+	"&uring;":                           true,
+	"&urtri;":                           true,
+	"&uscr;":                            true,
+	"&utdot;":                           true,
+	"&utilde;":                          true,
+	"&utri;":                            true,
+	"&utrif;":                           true,
+	"&uuarr;":                           true,
+	"&uuml":                             true,
+	"&uuml;":                            true,
+	"&uwangle;":                         true,
+	"&vArr;":                            true,
+	"&vBar;":                            true,
+	"&vBarv;":                           true,
+	"&vDash;":                           true,
+	"&vangrt;":                          true,
+	"&varepsilon;":                      true,
+	"&varkappa;":                        true,
+	"&varnothing;":                      true,
+	"&varphi;":                          true,
+	"&varpi;":                           true,
+	"&varpropto;":                       true,
+	"&varr;":                            true,
+	"&varrho;":                          true,
+	"&varsigma;":                        true,
+	"&varsubsetneq;":                    true,
+	"&varsubsetneqq;":                   true,
+	"&varsupsetneq;":                    true,
+	"&varsupsetneqq;":                   true,
+	"&vartheta;":                        true,
+	"&vartriangleleft;":                 true,
+	"&vartriangleright;":                true,
+	"&vcy;":                             true,
+	"&vdash;":                           true,
+	"&vee;":                             true,
+	"&veebar;":                          true,
+	"&veeeq;":                           true,
+	"&vellip;":                          true,
+	"&verbar;":                          true,
+	"&vert;":                            true,
+	"&vfr;":                             true,
+	"&vltri;":                           true,
+	"&vnsub;":                           true,
+	"&vnsup;":                           true,
+	"&vopf;":                            true,
+	"&vprop;":                           true,
+	"&vrtri;":                           true,
+	"&vscr;":                            true,
+	"&vsubnE;":                          true,
+	"&vsubne;":                          true,
+	"&vsupnE;":                          true,
+	"&vsupne;":                          true,
+	"&vzigzag;":                         true,
+	"&wcirc;":                           true,
+	"&wedbar;":                          true,
+	"&wedge;":                           true,
+	"&wedgeq;":                          true,
+	"&weierp;":                          true,
+	"&wfr;":                             true,
+	"&wopf;":                            true,
+	"&wp;":                              true,
+	"&wr;":                              true,
+	"&wreath;":                          true,
+	"&wscr;":                            true,
+	"&xcap;":                            true,
+	"&xcirc;":                           true,
+	"&xcup;":                            true,
+	"&xdtri;":                           true,
+	"&xfr;":                             true,
+	"&xhArr;":                           true,
+	"&xharr;":                           true,
+	"&xi;":                              true,
+	"&xlArr;":                           true,
+	"&xlarr;":                           true,
+	"&xmap;":                            true,
+	"&xnis;":                            true,
+	"&xodot;":                           true,
+	"&xopf;":                            true,
+	"&xoplus;":                          true,
+	"&xotime;":                          true,
+	"&xrArr;":                           true,
+	"&xrarr;":                           true,
+	"&xscr;":                            true,
+	"&xsqcup;":                          true,
+	"&xuplus;":                          true,
+	"&xutri;":                           true,
+	"&xvee;":                            true,
+	"&xwedge;":                          true,
+	"&yacute":                           true,
+	"&yacute;":                          true,
+	"&yacy;":                            true,
+	"&ycirc;":                           true,
+	"&ycy;":                             true,
+	"&yen":                              true,
+	"&yen;":                             true,
+	"&yfr;":                             true,
+	"&yicy;":                            true,
+	"&yopf;":                            true,
+	"&yscr;":                            true,
+	"&yucy;":                            true,
+	"&yuml":                             true,
+	"&yuml;":                            true,
+	"&zacute;":                          true,
+	"&zcaron;":                          true,
+	"&zcy;":                             true,
+	"&zdot;":                            true,
+	"&zeetrf;":                          true,
+	"&zeta;":                            true,
+	"&zfr;":                             true,
+	"&zhcy;":                            true,
+	"&zigrarr;":                         true,
+	"&zopf;":                            true,
+	"&zscr;":                            true,
+	"&zwj;":                             true,
+	"&zwnj;":                            true,
+}
diff --git a/vendor/github.com/russross/blackfriday/v2/esc.go b/vendor/github.com/russross/blackfriday/v2/esc.go
new file mode 100644
index 000000000000..6ab60102c9bf
--- /dev/null
+++ b/vendor/github.com/russross/blackfriday/v2/esc.go
@@ -0,0 +1,70 @@
+package blackfriday
+
+import (
+	"html"
+	"io"
+)
+
+var htmlEscaper = [256][]byte{
+	'&': []byte("&amp;"),
+	'<': []byte("&lt;"),
+	'>': []byte("&gt;"),
+	'"': []byte("&quot;"),
+}
+
+func escapeHTML(w io.Writer, s []byte) {
+	escapeEntities(w, s, false)
+}
+
+func escapeAllHTML(w io.Writer, s []byte) {
+	escapeEntities(w, s, true)
+}
+
+func escapeEntities(w io.Writer, s []byte, escapeValidEntities bool) {
+	var start, end int
+	for end < len(s) {
+		escSeq := htmlEscaper[s[end]]
+		if escSeq != nil {
+			isEntity, entityEnd := nodeIsEntity(s, end)
+			if isEntity && !escapeValidEntities {
+				w.Write(s[start : entityEnd+1])
+				start = entityEnd + 1
+			} else {
+				w.Write(s[start:end])
+				w.Write(escSeq)
+				start = end + 1
+			}
+		}
+		end++
+	}
+	if start < len(s) && end <= len(s) {
+		w.Write(s[start:end])
+	}
+}
+
+func nodeIsEntity(s []byte, end int) (isEntity bool, endEntityPos int) {
+	isEntity = false
+	endEntityPos = end + 1
+
+	if s[end] == '&' {
+		for endEntityPos < len(s) {
+			if s[endEntityPos] == ';' {
+				if entities[string(s[end:endEntityPos+1])] {
+					isEntity = true
+					break
+				}
+			}
+			if !isalnum(s[endEntityPos]) && s[endEntityPos] != '&' && s[endEntityPos] != '#' {
+				break
+			}
+			endEntityPos++
+		}
+	}
+
+	return isEntity, endEntityPos
+}
+
+func escLink(w io.Writer, text []byte) {
+	unesc := html.UnescapeString(string(text))
+	escapeHTML(w, []byte(unesc))
+}
diff --git a/vendor/github.com/russross/blackfriday/v2/html.go b/vendor/github.com/russross/blackfriday/v2/html.go
new file mode 100644
index 000000000000..cb4f26e30fd5
--- /dev/null
+++ b/vendor/github.com/russross/blackfriday/v2/html.go
@@ -0,0 +1,952 @@
+//
+// Blackfriday Markdown Processor
+// Available at http://github.com/russross/blackfriday
+//
+// Copyright © 2011 Russ Ross <russ@russross.com>.
+// Distributed under the Simplified BSD License.
+// See README.md for details.
+//
+
+//
+//
+// HTML rendering backend
+//
+//
+
+package blackfriday
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"regexp"
+	"strings"
+)
+
+// HTMLFlags control optional behavior of HTML renderer.
+type HTMLFlags int
+
+// HTML renderer configuration options.
+const (
+	HTMLFlagsNone           HTMLFlags = 0
+	SkipHTML                HTMLFlags = 1 << iota // Skip preformatted HTML blocks
+	SkipImages                                    // Skip embedded images
+	SkipLinks                                     // Skip all links
+	Safelink                                      // Only link to trusted protocols
+	NofollowLinks                                 // Only link with rel="nofollow"
+	NoreferrerLinks                               // Only link with rel="noreferrer"
+	NoopenerLinks                                 // Only link with rel="noopener"
+	HrefTargetBlank                               // Add a blank target
+	CompletePage                                  // Generate a complete HTML page
+	UseXHTML                                      // Generate XHTML output instead of HTML
+	FootnoteReturnLinks                           // Generate a link at the end of a footnote to return to the source
+	Smartypants                                   // Enable smart punctuation substitutions
+	SmartypantsFractions                          // Enable smart fractions (with Smartypants)
+	SmartypantsDashes                             // Enable smart dashes (with Smartypants)
+	SmartypantsLatexDashes                        // Enable LaTeX-style dashes (with Smartypants)
+	SmartypantsAngledQuotes                       // Enable angled double quotes (with Smartypants) for double quotes rendering
+	SmartypantsQuotesNBSP                         // Enable « French guillemets » (with Smartypants)
+	TOC                                           // Generate a table of contents
+)
+
+var (
+	htmlTagRe = regexp.MustCompile("(?i)^" + htmlTag)
+)
+
+const (
+	htmlTag = "(?:" + openTag + "|" + closeTag + "|" + htmlComment + "|" +
+		processingInstruction + "|" + declaration + "|" + cdata + ")"
+	closeTag              = "</" + tagName + "\\s*[>]"
+	openTag               = "<" + tagName + attribute + "*" + "\\s*/?>"
+	attribute             = "(?:" + "\\s+" + attributeName + attributeValueSpec + "?)"
+	attributeValue        = "(?:" + unquotedValue + "|" + singleQuotedValue + "|" + doubleQuotedValue + ")"
+	attributeValueSpec    = "(?:" + "\\s*=" + "\\s*" + attributeValue + ")"
+	attributeName         = "[a-zA-Z_:][a-zA-Z0-9:._-]*"
+	cdata                 = "<!\\[CDATA\\[[\\s\\S]*?\\]\\]>"
+	declaration           = "<![A-Z]+" + "\\s+[^>]*>"
+	doubleQuotedValue     = "\"[^\"]*\""
+	htmlComment           = "|"
+	processingInstruction = "[<][?].*?[?][>]"
+	singleQuotedValue     = "'[^']*'"
+	tagName               = "[A-Za-z][A-Za-z0-9-]*"
+	unquotedValue         = "[^\"'=<>`\\x00-\\x20]+"
+)
+
+// HTMLRendererParameters is a collection of supplementary parameters tweaking
+// the behavior of various parts of HTML renderer.
+type HTMLRendererParameters struct {
+	// Prepend this text to each relative URL.
+	AbsolutePrefix string
+	// Add this text to each footnote anchor, to ensure uniqueness.
+	FootnoteAnchorPrefix string
+	// Show this text inside the <a> tag for a footnote return link, if the
+	// HTML_FOOTNOTE_RETURN_LINKS flag is enabled. If blank, the string
+	// <sup>[return]</sup> is used.
+	FootnoteReturnLinkContents string
+	// If set, add this text to the front of each Heading ID, to ensure
+	// uniqueness.
+	HeadingIDPrefix string
+	// If set, add this text to the back of each Heading ID, to ensure uniqueness.
+	HeadingIDSuffix string
+	// Increase heading levels: if the offset is 1, <h1> becomes <h2> etc.
+	// Negative offset is also valid.
+	// Resulting levels are clipped between 1 and 6.
+	HeadingLevelOffset int
+
+	Title string // Document title (used if CompletePage is set)
+	CSS   string // Optional CSS file URL (used if CompletePage is set)
+	Icon  string // Optional icon file URL (used if CompletePage is set)
+
+	Flags HTMLFlags // Flags allow customizing this renderer's behavior
+}
+
+// HTMLRenderer is a type that implements the Renderer interface for HTML output.
+//
+// Do not create this directly, instead use the NewHTMLRenderer function.
+type HTMLRenderer struct {
+	HTMLRendererParameters
+
+	closeTag string // how to end singleton tags: either " />" or ">"
+
+	// Track heading IDs to prevent ID collision in a single generation.
+	headingIDs map[string]int
+
+	lastOutputLen int
+	disableTags   int
+
+	sr *SPRenderer
+}
+
+const (
+	xhtmlClose = " />"
+	htmlClose  = ">"
+)
+
+// NewHTMLRenderer creates and configures an HTMLRenderer object, which
+// satisfies the Renderer interface.
+func NewHTMLRenderer(params HTMLRendererParameters) *HTMLRenderer {
+	// configure the rendering engine
+	closeTag := htmlClose
+	if params.Flags&UseXHTML != 0 {
+		closeTag = xhtmlClose
+	}
+
+	if params.FootnoteReturnLinkContents == "" {
+		// U+FE0E is VARIATION SELECTOR-15.
+		// It suppresses automatic emoji presentation of the preceding
+		// U+21A9 LEFTWARDS ARROW WITH HOOK on iOS and iPadOS.
+		params.FootnoteReturnLinkContents = "<span aria-label='Return'>↩\ufe0e</span>"
+	}
+
+	return &HTMLRenderer{
+		HTMLRendererParameters: params,
+
+		closeTag:   closeTag,
+		headingIDs: make(map[string]int),
+
+		sr: NewSmartypantsRenderer(params.Flags),
+	}
+}
+
+func isHTMLTag(tag []byte, tagname string) bool {
+	found, _ := findHTMLTagPos(tag, tagname)
+	return found
+}
+
+// Look for a character, but ignore it when it's in any kind of quotes, it
+// might be JavaScript
+func skipUntilCharIgnoreQuotes(html []byte, start int, char byte) int {
+	inSingleQuote := false
+	inDoubleQuote := false
+	inGraveQuote := false
+	i := start
+	for i < len(html) {
+		switch {
+		case html[i] == char && !inSingleQuote && !inDoubleQuote && !inGraveQuote:
+			return i
+		case html[i] == '\'':
+			inSingleQuote = !inSingleQuote
+		case html[i] == '"':
+			inDoubleQuote = !inDoubleQuote
+		case html[i] == '`':
+			inGraveQuote = !inGraveQuote
+		}
+		i++
+	}
+	return start
+}
+
+func findHTMLTagPos(tag []byte, tagname string) (bool, int) {
+	i := 0
+	if i < len(tag) && tag[0] != '<' {
+		return false, -1
+	}
+	i++
+	i = skipSpace(tag, i)
+
+	if i < len(tag) && tag[i] == '/' {
+		i++
+	}
+
+	i = skipSpace(tag, i)
+	j := 0
+	for ; i < len(tag); i, j = i+1, j+1 {
+		if j >= len(tagname) {
+			break
+		}
+
+		if strings.ToLower(string(tag[i]))[0] != tagname[j] {
+			return false, -1
+		}
+	}
+
+	if i == len(tag) {
+		return false, -1
+	}
+
+	rightAngle := skipUntilCharIgnoreQuotes(tag, i, '>')
+	if rightAngle >= i {
+		return true, rightAngle
+	}
+
+	return false, -1
+}
+
+func skipSpace(tag []byte, i int) int {
+	for i < len(tag) && isspace(tag[i]) {
+		i++
+	}
+	return i
+}
+
+func isRelativeLink(link []byte) (yes bool) {
+	// a tag begin with '#'
+	if link[0] == '#' {
+		return true
+	}
+
+	// link begin with '/' but not '//', the second maybe a protocol relative link
+	if len(link) >= 2 && link[0] == '/' && link[1] != '/' {
+		return true
+	}
+
+	// only the root '/'
+	if len(link) == 1 && link[0] == '/' {
+		return true
+	}
+
+	// current directory : begin with "./"
+	if bytes.HasPrefix(link, []byte("./")) {
+		return true
+	}
+
+	// parent directory : begin with "../"
+	if bytes.HasPrefix(link, []byte("../")) {
+		return true
+	}
+
+	return false
+}
+
+func (r *HTMLRenderer) ensureUniqueHeadingID(id string) string {
+	for count, found := r.headingIDs[id]; found; count, found = r.headingIDs[id] {
+		tmp := fmt.Sprintf("%s-%d", id, count+1)
+
+		if _, tmpFound := r.headingIDs[tmp]; !tmpFound {
+			r.headingIDs[id] = count + 1
+			id = tmp
+		} else {
+			id = id + "-1"
+		}
+	}
+
+	if _, found := r.headingIDs[id]; !found {
+		r.headingIDs[id] = 0
+	}
+
+	return id
+}
+
+func (r *HTMLRenderer) addAbsPrefix(link []byte) []byte {
+	if r.AbsolutePrefix != "" && isRelativeLink(link) && link[0] != '.' {
+		newDest := r.AbsolutePrefix
+		if link[0] != '/' {
+			newDest += "/"
+		}
+		newDest += string(link)
+		return []byte(newDest)
+	}
+	return link
+}
+
+func appendLinkAttrs(attrs []string, flags HTMLFlags, link []byte) []string {
+	if isRelativeLink(link) {
+		return attrs
+	}
+	val := []string{}
+	if flags&NofollowLinks != 0 {
+		val = append(val, "nofollow")
+	}
+	if flags&NoreferrerLinks != 0 {
+		val = append(val, "noreferrer")
+	}
+	if flags&NoopenerLinks != 0 {
+		val = append(val, "noopener")
+	}
+	if flags&HrefTargetBlank != 0 {
+		attrs = append(attrs, "target=\"_blank\"")
+	}
+	if len(val) == 0 {
+		return attrs
+	}
+	attr := fmt.Sprintf("rel=%q", strings.Join(val, " "))
+	return append(attrs, attr)
+}
+
+func isMailto(link []byte) bool {
+	return bytes.HasPrefix(link, []byte("mailto:"))
+}
+
+func needSkipLink(flags HTMLFlags, dest []byte) bool {
+	if flags&SkipLinks != 0 {
+		return true
+	}
+	return flags&Safelink != 0 && !isSafeLink(dest) && !isMailto(dest)
+}
+
+func isSmartypantable(node *Node) bool {
+	pt := node.Parent.Type
+	return pt != Link && pt != CodeBlock && pt != Code
+}
+
+func appendLanguageAttr(attrs []string, info []byte) []string {
+	if len(info) == 0 {
+		return attrs
+	}
+	endOfLang := bytes.IndexAny(info, "\t ")
+	if endOfLang < 0 {
+		endOfLang = len(info)
+	}
+	return append(attrs, fmt.Sprintf("class=\"language-%s\"", info[:endOfLang]))
+}
+
+func (r *HTMLRenderer) tag(w io.Writer, name []byte, attrs []string) {
+	w.Write(name)
+	if len(attrs) > 0 {
+		w.Write(spaceBytes)
+		w.Write([]byte(strings.Join(attrs, " ")))
+	}
+	w.Write(gtBytes)
+	r.lastOutputLen = 1
+}
+
+func footnoteRef(prefix string, node *Node) []byte {
+	urlFrag := prefix + string(slugify(node.Destination))
+	anchor := fmt.Sprintf(`<a href="#fn:%s">%d</a>`, urlFrag, node.NoteID)
+	return []byte(fmt.Sprintf(`<sup class="footnote-ref" id="fnref:%s">%s</sup>`, urlFrag, anchor))
+}
+
+func footnoteItem(prefix string, slug []byte) []byte {
+	return []byte(fmt.Sprintf(`<li id="fn:%s%s">`, prefix, slug))
+}
+
+func footnoteReturnLink(prefix, returnLink string, slug []byte) []byte {
+	const format = ` <a class="footnote-return" href="#fnref:%s%s">%s</a>`
+	return []byte(fmt.Sprintf(format, prefix, slug, returnLink))
+}
+
+func itemOpenCR(node *Node) bool {
+	if node.Prev == nil {
+		return false
+	}
+	ld := node.Parent.ListData
+	return !ld.Tight && ld.ListFlags&ListTypeDefinition == 0
+}
+
+func skipParagraphTags(node *Node) bool {
+	grandparent := node.Parent.Parent
+	if grandparent == nil || grandparent.Type != List {
+		return false
+	}
+	tightOrTerm := grandparent.Tight || node.Parent.ListFlags&ListTypeTerm != 0
+	return grandparent.Type == List && tightOrTerm
+}
+
+func cellAlignment(align CellAlignFlags) string {
+	switch align {
+	case TableAlignmentLeft:
+		return "left"
+	case TableAlignmentRight:
+		return "right"
+	case TableAlignmentCenter:
+		return "center"
+	default:
+		return ""
+	}
+}
+
+func (r *HTMLRenderer) out(w io.Writer, text []byte) {
+	if r.disableTags > 0 {
+		w.Write(htmlTagRe.ReplaceAll(text, []byte{}))
+	} else {
+		w.Write(text)
+	}
+	r.lastOutputLen = len(text)
+}
+
+func (r *HTMLRenderer) cr(w io.Writer) {
+	if r.lastOutputLen > 0 {
+		r.out(w, nlBytes)
+	}
+}
+
+var (
+	nlBytes    = []byte{'\n'}
+	gtBytes    = []byte{'>'}
+	spaceBytes = []byte{' '}
+)
+
+var (
+	brTag              = []byte("<br>")
+	brXHTMLTag         = []byte("<br />")
+	emTag              = []byte("<em>")
+	emCloseTag         = []byte("</em>")
+	strongTag          = []byte("<strong>")
+	strongCloseTag     = []byte("</strong>")
+	delTag             = []byte("<del>")
+	delCloseTag        = []byte("</del>")
+	ttTag              = []byte("<tt>")
+	ttCloseTag         = []byte("</tt>")
+	aTag               = []byte("<a")
+	aCloseTag          = []byte("</a>")
+	preTag             = []byte("<pre>")
+	preCloseTag        = []byte("</pre>")
+	codeTag            = []byte("<code>")
+	codeCloseTag       = []byte("</code>")
+	pTag               = []byte("<p>")
+	pCloseTag          = []byte("</p>")
+	blockquoteTag      = []byte("<blockquote>")
+	blockquoteCloseTag = []byte("</blockquote>")
+	hrTag              = []byte("<hr>")
+	hrXHTMLTag         = []byte("<hr />")
+	ulTag              = []byte("<ul>")
+	ulCloseTag         = []byte("</ul>")
+	olTag              = []byte("<ol>")
+	olCloseTag         = []byte("</ol>")
+	dlTag              = []byte("<dl>")
+	dlCloseTag         = []byte("</dl>")
+	liTag              = []byte("<li>")
+	liCloseTag         = []byte("</li>")
+	ddTag              = []byte("<dd>")
+	ddCloseTag         = []byte("</dd>")
+	dtTag              = []byte("<dt>")
+	dtCloseTag         = []byte("</dt>")
+	tableTag           = []byte("<table>")
+	tableCloseTag      = []byte("</table>")
+	tdTag              = []byte("<td")
+	tdCloseTag         = []byte("</td>")
+	thTag              = []byte("<th")
+	thCloseTag         = []byte("</th>")
+	theadTag           = []byte("<thead>")
+	theadCloseTag      = []byte("</thead>")
+	tbodyTag           = []byte("<tbody>")
+	tbodyCloseTag      = []byte("</tbody>")
+	trTag              = []byte("<tr>")
+	trCloseTag         = []byte("</tr>")
+	h1Tag              = []byte("<h1")
+	h1CloseTag         = []byte("</h1>")
+	h2Tag              = []byte("<h2")
+	h2CloseTag         = []byte("</h2>")
+	h3Tag              = []byte("<h3")
+	h3CloseTag         = []byte("</h3>")
+	h4Tag              = []byte("<h4")
+	h4CloseTag         = []byte("</h4>")
+	h5Tag              = []byte("<h5")
+	h5CloseTag         = []byte("</h5>")
+	h6Tag              = []byte("<h6")
+	h6CloseTag         = []byte("</h6>")
+
+	footnotesDivBytes      = []byte("\n<div class=\"footnotes\">\n\n")
+	footnotesCloseDivBytes = []byte("\n</div>\n")
+)
+
+func headingTagsFromLevel(level int) ([]byte, []byte) {
+	if level <= 1 {
+		return h1Tag, h1CloseTag
+	}
+	switch level {
+	case 2:
+		return h2Tag, h2CloseTag
+	case 3:
+		return h3Tag, h3CloseTag
+	case 4:
+		return h4Tag, h4CloseTag
+	case 5:
+		return h5Tag, h5CloseTag
+	}
+	return h6Tag, h6CloseTag
+}
+
+func (r *HTMLRenderer) outHRTag(w io.Writer) {
+	if r.Flags&UseXHTML == 0 {
+		r.out(w, hrTag)
+	} else {
+		r.out(w, hrXHTMLTag)
+	}
+}
+
+// RenderNode is a default renderer of a single node of a syntax tree. For
+// block nodes it will be called twice: first time with entering=true, second
+// time with entering=false, so that it could know when it's working on an open
+// tag and when on close. It writes the result to w.
+//
+// The return value is a way to tell the calling walker to adjust its walk
+// pattern: e.g. it can terminate the traversal by returning Terminate. Or it
+// can ask the walker to skip a subtree of this node by returning SkipChildren.
+// The typical behavior is to return GoToNext, which asks for the usual
+// traversal to the next node.
+func (r *HTMLRenderer) RenderNode(w io.Writer, node *Node, entering bool) WalkStatus {
+	attrs := []string{}
+	switch node.Type {
+	case Text:
+		if r.Flags&Smartypants != 0 {
+			var tmp bytes.Buffer
+			escapeHTML(&tmp, node.Literal)
+			r.sr.Process(w, tmp.Bytes())
+		} else {
+			if node.Parent.Type == Link {
+				escLink(w, node.Literal)
+			} else {
+				escapeHTML(w, node.Literal)
+			}
+		}
+	case Softbreak:
+		r.cr(w)
+		// TODO: make it configurable via out(renderer.softbreak)
+	case Hardbreak:
+		if r.Flags&UseXHTML == 0 {
+			r.out(w, brTag)
+		} else {
+			r.out(w, brXHTMLTag)
+		}
+		r.cr(w)
+	case Emph:
+		if entering {
+			r.out(w, emTag)
+		} else {
+			r.out(w, emCloseTag)
+		}
+	case Strong:
+		if entering {
+			r.out(w, strongTag)
+		} else {
+			r.out(w, strongCloseTag)
+		}
+	case Del:
+		if entering {
+			r.out(w, delTag)
+		} else {
+			r.out(w, delCloseTag)
+		}
+	case HTMLSpan:
+		if r.Flags&SkipHTML != 0 {
+			break
+		}
+		r.out(w, node.Literal)
+	case Link:
+		// mark it but don't link it if it is not a safe link: no smartypants
+		dest := node.LinkData.Destination
+		if needSkipLink(r.Flags, dest) {
+			if entering {
+				r.out(w, ttTag)
+			} else {
+				r.out(w, ttCloseTag)
+			}
+		} else {
+			if entering {
+				dest = r.addAbsPrefix(dest)
+				var hrefBuf bytes.Buffer
+				hrefBuf.WriteString("href=\"")
+				escLink(&hrefBuf, dest)
+				hrefBuf.WriteByte('"')
+				attrs = append(attrs, hrefBuf.String())
+				if node.NoteID != 0 {
+					r.out(w, footnoteRef(r.FootnoteAnchorPrefix, node))
+					break
+				}
+				attrs = appendLinkAttrs(attrs, r.Flags, dest)
+				if len(node.LinkData.Title) > 0 {
+					var titleBuff bytes.Buffer
+					titleBuff.WriteString("title=\"")
+					escapeHTML(&titleBuff, node.LinkData.Title)
+					titleBuff.WriteByte('"')
+					attrs = append(attrs, titleBuff.String())
+				}
+				r.tag(w, aTag, attrs)
+			} else {
+				if node.NoteID != 0 {
+					break
+				}
+				r.out(w, aCloseTag)
+			}
+		}
+	case Image:
+		if r.Flags&SkipImages != 0 {
+			return SkipChildren
+		}
+		if entering {
+			dest := node.LinkData.Destination
+			dest = r.addAbsPrefix(dest)
+			if r.disableTags == 0 {
+				//if options.safe && potentiallyUnsafe(dest) {
+				//out(w, `<img src="" alt="`)
+				//} else {
+				r.out(w, []byte(`<img src="`))
+				escLink(w, dest)
+				r.out(w, []byte(`" alt="`))
+				//}
+			}
+			r.disableTags++
+		} else {
+			r.disableTags--
+			if r.disableTags == 0 {
+				if node.LinkData.Title != nil {
+					r.out(w, []byte(`" title="`))
+					escapeHTML(w, node.LinkData.Title)
+				}
+				r.out(w, []byte(`" />`))
+			}
+		}
+	case Code:
+		r.out(w, codeTag)
+		escapeAllHTML(w, node.Literal)
+		r.out(w, codeCloseTag)
+	case Document:
+		break
+	case Paragraph:
+		if skipParagraphTags(node) {
+			break
+		}
+		if entering {
+			// TODO: untangle this clusterfuck about when the newlines need
+			// to be added and when not.
+			if node.Prev != nil {
+				switch node.Prev.Type {
+				case HTMLBlock, List, Paragraph, Heading, CodeBlock, BlockQuote, HorizontalRule:
+					r.cr(w)
+				}
+			}
+			if node.Parent.Type == BlockQuote && node.Prev == nil {
+				r.cr(w)
+			}
+			r.out(w, pTag)
+		} else {
+			r.out(w, pCloseTag)
+			if !(node.Parent.Type == Item && node.Next == nil) {
+				r.cr(w)
+			}
+		}
+	case BlockQuote:
+		if entering {
+			r.cr(w)
+			r.out(w, blockquoteTag)
+		} else {
+			r.out(w, blockquoteCloseTag)
+			r.cr(w)
+		}
+	case HTMLBlock:
+		if r.Flags&SkipHTML != 0 {
+			break
+		}
+		r.cr(w)
+		r.out(w, node.Literal)
+		r.cr(w)
+	case Heading:
+		headingLevel := r.HTMLRendererParameters.HeadingLevelOffset + node.Level
+		openTag, closeTag := headingTagsFromLevel(headingLevel)
+		if entering {
+			if node.IsTitleblock {
+				attrs = append(attrs, `class="title"`)
+			}
+			if node.HeadingID != "" {
+				id := r.ensureUniqueHeadingID(node.HeadingID)
+				if r.HeadingIDPrefix != "" {
+					id = r.HeadingIDPrefix + id
+				}
+				if r.HeadingIDSuffix != "" {
+					id = id + r.HeadingIDSuffix
+				}
+				attrs = append(attrs, fmt.Sprintf(`id="%s"`, id))
+			}
+			r.cr(w)
+			r.tag(w, openTag, attrs)
+		} else {
+			r.out(w, closeTag)
+			if !(node.Parent.Type == Item && node.Next == nil) {
+				r.cr(w)
+			}
+		}
+	case HorizontalRule:
+		r.cr(w)
+		r.outHRTag(w)
+		r.cr(w)
+	case List:
+		openTag := ulTag
+		closeTag := ulCloseTag
+		if node.ListFlags&ListTypeOrdered != 0 {
+			openTag = olTag
+			closeTag = olCloseTag
+		}
+		if node.ListFlags&ListTypeDefinition != 0 {
+			openTag = dlTag
+			closeTag = dlCloseTag
+		}
+		if entering {
+			if node.IsFootnotesList {
+				r.out(w, footnotesDivBytes)
+				r.outHRTag(w)
+				r.cr(w)
+			}
+			r.cr(w)
+			if node.Parent.Type == Item && node.Parent.Parent.Tight {
+				r.cr(w)
+			}
+			r.tag(w, openTag[:len(openTag)-1], attrs)
+			r.cr(w)
+		} else {
+			r.out(w, closeTag)
+			//cr(w)
+			//if node.parent.Type != Item {
+			//	cr(w)
+			//}
+			if node.Parent.Type == Item && node.Next != nil {
+				r.cr(w)
+			}
+			if node.Parent.Type == Document || node.Parent.Type == BlockQuote {
+				r.cr(w)
+			}
+			if node.IsFootnotesList {
+				r.out(w, footnotesCloseDivBytes)
+			}
+		}
+	case Item:
+		openTag := liTag
+		closeTag := liCloseTag
+		if node.ListFlags&ListTypeDefinition != 0 {
+			openTag = ddTag
+			closeTag = ddCloseTag
+		}
+		if node.ListFlags&ListTypeTerm != 0 {
+			openTag = dtTag
+			closeTag = dtCloseTag
+		}
+		if entering {
+			if itemOpenCR(node) {
+				r.cr(w)
+			}
+			if node.ListData.RefLink != nil {
+				slug := slugify(node.ListData.RefLink)
+				r.out(w, footnoteItem(r.FootnoteAnchorPrefix, slug))
+				break
+			}
+			r.out(w, openTag)
+		} else {
+			if node.ListData.RefLink != nil {
+				slug := slugify(node.ListData.RefLink)
+				if r.Flags&FootnoteReturnLinks != 0 {
+					r.out(w, footnoteReturnLink(r.FootnoteAnchorPrefix, r.FootnoteReturnLinkContents, slug))
+				}
+			}
+			r.out(w, closeTag)
+			r.cr(w)
+		}
+	case CodeBlock:
+		attrs = appendLanguageAttr(attrs, node.Info)
+		r.cr(w)
+		r.out(w, preTag)
+		r.tag(w, codeTag[:len(codeTag)-1], attrs)
+		escapeAllHTML(w, node.Literal)
+		r.out(w, codeCloseTag)
+		r.out(w, preCloseTag)
+		if node.Parent.Type != Item {
+			r.cr(w)
+		}
+	case Table:
+		if entering {
+			r.cr(w)
+			r.out(w, tableTag)
+		} else {
+			r.out(w, tableCloseTag)
+			r.cr(w)
+		}
+	case TableCell:
+		openTag := tdTag
+		closeTag := tdCloseTag
+		if node.IsHeader {
+			openTag = thTag
+			closeTag = thCloseTag
+		}
+		if entering {
+			align := cellAlignment(node.Align)
+			if align != "" {
+				attrs = append(attrs, fmt.Sprintf(`align="%s"`, align))
+			}
+			if node.Prev == nil {
+				r.cr(w)
+			}
+			r.tag(w, openTag, attrs)
+		} else {
+			r.out(w, closeTag)
+			r.cr(w)
+		}
+	case TableHead:
+		if entering {
+			r.cr(w)
+			r.out(w, theadTag)
+		} else {
+			r.out(w, theadCloseTag)
+			r.cr(w)
+		}
+	case TableBody:
+		if entering {
+			r.cr(w)
+			r.out(w, tbodyTag)
+			// XXX: this is to adhere to a rather silly test. Should fix test.
+			if node.FirstChild == nil {
+				r.cr(w)
+			}
+		} else {
+			r.out(w, tbodyCloseTag)
+			r.cr(w)
+		}
+	case TableRow:
+		if entering {
+			r.cr(w)
+			r.out(w, trTag)
+		} else {
+			r.out(w, trCloseTag)
+			r.cr(w)
+		}
+	default:
+		panic("Unknown node type " + node.Type.String())
+	}
+	return GoToNext
+}
+
+// RenderHeader writes HTML document preamble and TOC if requested.
+func (r *HTMLRenderer) RenderHeader(w io.Writer, ast *Node) {
+	r.writeDocumentHeader(w)
+	if r.Flags&TOC != 0 {
+		r.writeTOC(w, ast)
+	}
+}
+
+// RenderFooter writes HTML document footer.
+func (r *HTMLRenderer) RenderFooter(w io.Writer, ast *Node) {
+	if r.Flags&CompletePage == 0 {
+		return
+	}
+	io.WriteString(w, "\n</body>\n</html>\n")
+}
+
+func (r *HTMLRenderer) writeDocumentHeader(w io.Writer) {
+	if r.Flags&CompletePage == 0 {
+		return
+	}
+	ending := ""
+	if r.Flags&UseXHTML != 0 {
+		io.WriteString(w, "<!DOCTYPE html PUBLIC \"-//W3C//DTD XHTML 1.0 Transitional//EN\" ")
+		io.WriteString(w, "\"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd\">\n")
+		io.WriteString(w, "<html xmlns=\"http://www.w3.org/1999/xhtml\">\n")
+		ending = " /"
+	} else {
+		io.WriteString(w, "<!DOCTYPE html>\n")
+		io.WriteString(w, "<html>\n")
+	}
+	io.WriteString(w, "<head>\n")
+	io.WriteString(w, "  <title>")
+	if r.Flags&Smartypants != 0 {
+		r.sr.Process(w, []byte(r.Title))
+	} else {
+		escapeHTML(w, []byte(r.Title))
+	}
+	io.WriteString(w, "</title>\n")
+	io.WriteString(w, "  <meta name=\"GENERATOR\" content=\"Blackfriday Markdown Processor v")
+	io.WriteString(w, Version)
+	io.WriteString(w, "\"")
+	io.WriteString(w, ending)
+	io.WriteString(w, ">\n")
+	io.WriteString(w, "  <meta charset=\"utf-8\"")
+	io.WriteString(w, ending)
+	io.WriteString(w, ">\n")
+	if r.CSS != "" {
+		io.WriteString(w, "  <link rel=\"stylesheet\" type=\"text/css\" href=\"")
+		escapeHTML(w, []byte(r.CSS))
+		io.WriteString(w, "\"")
+		io.WriteString(w, ending)
+		io.WriteString(w, ">\n")
+	}
+	if r.Icon != "" {
+		io.WriteString(w, "  <link rel=\"icon\" type=\"image/x-icon\" href=\"")
+		escapeHTML(w, []byte(r.Icon))
+		io.WriteString(w, "\"")
+		io.WriteString(w, ending)
+		io.WriteString(w, ">\n")
+	}
+	io.WriteString(w, "</head>\n")
+	io.WriteString(w, "<body>\n\n")
+}
+
+func (r *HTMLRenderer) writeTOC(w io.Writer, ast *Node) {
+	buf := bytes.Buffer{}
+
+	inHeading := false
+	tocLevel := 0
+	headingCount := 0
+
+	ast.Walk(func(node *Node, entering bool) WalkStatus {
+		if node.Type == Heading && !node.HeadingData.IsTitleblock {
+			inHeading = entering
+			if entering {
+				node.HeadingID = fmt.Sprintf("toc_%d", headingCount)
+				if node.Level == tocLevel {
+					buf.WriteString("</li>\n\n<li>")
+				} else if node.Level < tocLevel {
+					for node.Level < tocLevel {
+						tocLevel--
+						buf.WriteString("</li>\n</ul>")
+					}
+					buf.WriteString("</li>\n\n<li>")
+				} else {
+					for node.Level > tocLevel {
+						tocLevel++
+						buf.WriteString("\n<ul>\n<li>")
+					}
+				}
+
+				fmt.Fprintf(&buf, `<a href="#toc_%d">`, headingCount)
+				headingCount++
+			} else {
+				buf.WriteString("</a>")
+			}
+			return GoToNext
+		}
+
+		if inHeading {
+			return r.RenderNode(&buf, node, entering)
+		}
+
+		return GoToNext
+	})
+
+	for ; tocLevel > 0; tocLevel-- {
+		buf.WriteString("</li>\n</ul>")
+	}
+
+	if buf.Len() > 0 {
+		io.WriteString(w, "<nav>\n")
+		w.Write(buf.Bytes())
+		io.WriteString(w, "\n\n</nav>\n")
+	}
+	r.lastOutputLen = buf.Len()
+}
diff --git a/vendor/github.com/russross/blackfriday/v2/inline.go b/vendor/github.com/russross/blackfriday/v2/inline.go
new file mode 100644
index 000000000000..d45bd941726e
--- /dev/null
+++ b/vendor/github.com/russross/blackfriday/v2/inline.go
@@ -0,0 +1,1228 @@
+//
+// Blackfriday Markdown Processor
+// Available at http://github.com/russross/blackfriday
+//
+// Copyright © 2011 Russ Ross <russ@russross.com>.
+// Distributed under the Simplified BSD License.
+// See README.md for details.
+//
+
+//
+// Functions to parse inline elements.
+//
+
+package blackfriday
+
+import (
+	"bytes"
+	"regexp"
+	"strconv"
+)
+
+var (
+	urlRe    = `((https?|ftp):\/\/|\/)[-A-Za-z0-9+&@#\/%?=~_|!:,.;]+`
+	anchorRe = regexp.MustCompile(`^(<a\shref="` + urlRe + `"(\stitle="[^"<>]+")?\s?>` + urlRe + `<\/a>)`)
+
+	// https://www.w3.org/TR/html5/syntax.html#character-references
+	// highest unicode code point in 17 planes (2^20): 1,114,112d =
+	// 7 dec digits or 6 hex digits
+	// named entity references can be 2-31 characters with stuff like &lt;
+	// at one end and &CounterClockwiseContourIntegral; at the other. There
+	// are also sometimes numbers at the end, although this isn't inherent
+	// in the specification; there are never numbers anywhere else in
+	// current character references, though; see &frac34; and &blk12;, etc.
+	// https://www.w3.org/TR/html5/syntax.html#named-character-references
+	//
+	// entity := "&" (named group | number ref) ";"
+	// named group := [a-zA-Z]{2,31}[0-9]{0,2}
+	// number ref := "#" (dec ref | hex ref)
+	// dec ref := [0-9]{1,7}
+	// hex ref := ("x" | "X") [0-9a-fA-F]{1,6}
+	htmlEntityRe = regexp.MustCompile(`&([a-zA-Z]{2,31}[0-9]{0,2}|#([0-9]{1,7}|[xX][0-9a-fA-F]{1,6}));`)
+)
+
+// Functions to parse text within a block
+// Each function returns the number of chars taken care of
+// data is the complete block being rendered
+// offset is the number of valid chars before the current cursor
+
+func (p *Markdown) inline(currBlock *Node, data []byte) {
+	// handlers might call us recursively: enforce a maximum depth
+	if p.nesting >= p.maxNesting || len(data) == 0 {
+		return
+	}
+	p.nesting++
+	beg, end := 0, 0
+	for end < len(data) {
+		handler := p.inlineCallback[data[end]]
+		if handler != nil {
+			if consumed, node := handler(p, data, end); consumed == 0 {
+				// No action from the callback.
+				end++
+			} else {
+				// Copy inactive chars into the output.
+				currBlock.AppendChild(text(data[beg:end]))
+				if node != nil {
+					currBlock.AppendChild(node)
+				}
+				// Skip past whatever the callback used.
+				beg = end + consumed
+				end = beg
+			}
+		} else {
+			end++
+		}
+	}
+	if beg < len(data) {
+		if data[end-1] == '\n' {
+			end--
+		}
+		currBlock.AppendChild(text(data[beg:end]))
+	}
+	p.nesting--
+}
+
+// single and double emphasis parsing
+func emphasis(p *Markdown, data []byte, offset int) (int, *Node) {
+	data = data[offset:]
+	c := data[0]
+
+	if len(data) > 2 && data[1] != c {
+		// whitespace cannot follow an opening emphasis;
+		// strikethrough only takes two characters '~~'
+		if c == '~' || isspace(data[1]) {
+			return 0, nil
+		}
+		ret, node := helperEmphasis(p, data[1:], c)
+		if ret == 0 {
+			return 0, nil
+		}
+
+		return ret + 1, node
+	}
+
+	if len(data) > 3 && data[1] == c && data[2] != c {
+		if isspace(data[2]) {
+			return 0, nil
+		}
+		ret, node := helperDoubleEmphasis(p, data[2:], c)
+		if ret == 0 {
+			return 0, nil
+		}
+
+		return ret + 2, node
+	}
+
+	if len(data) > 4 && data[1] == c && data[2] == c && data[3] != c {
+		if c == '~' || isspace(data[3]) {
+			return 0, nil
+		}
+		ret, node := helperTripleEmphasis(p, data, 3, c)
+		if ret == 0 {
+			return 0, nil
+		}
+
+		return ret + 3, node
+	}
+
+	return 0, nil
+}
+
+func codeSpan(p *Markdown, data []byte, offset int) (int, *Node) {
+	data = data[offset:]
+
+	nb := 0
+
+	// count the number of backticks in the delimiter
+	for nb < len(data) && data[nb] == '`' {
+		nb++
+	}
+
+	// find the next delimiter
+	i, end := 0, 0
+	for end = nb; end < len(data) && i < nb; end++ {
+		if data[end] == '`' {
+			i++
+		} else {
+			i = 0
+		}
+	}
+
+	// no matching delimiter?
+	if i < nb && end >= len(data) {
+		return 0, nil
+	}
+
+	// trim outside whitespace
+	fBegin := nb
+	for fBegin < end && data[fBegin] == ' ' {
+		fBegin++
+	}
+
+	fEnd := end - nb
+	for fEnd > fBegin && data[fEnd-1] == ' ' {
+		fEnd--
+	}
+
+	// render the code span
+	if fBegin != fEnd {
+		code := NewNode(Code)
+		code.Literal = data[fBegin:fEnd]
+		return end, code
+	}
+
+	return end, nil
+}
+
+// newline preceded by two spaces becomes <br>
+func maybeLineBreak(p *Markdown, data []byte, offset int) (int, *Node) {
+	origOffset := offset
+	for offset < len(data) && data[offset] == ' ' {
+		offset++
+	}
+
+	if offset < len(data) && data[offset] == '\n' {
+		if offset-origOffset >= 2 {
+			return offset - origOffset + 1, NewNode(Hardbreak)
+		}
+		return offset - origOffset, nil
+	}
+	return 0, nil
+}
+
+// newline without two spaces works when HardLineBreak is enabled
+func lineBreak(p *Markdown, data []byte, offset int) (int, *Node) {
+	if p.extensions&HardLineBreak != 0 {
+		return 1, NewNode(Hardbreak)
+	}
+	return 0, nil
+}
+
+type linkType int
+
+const (
+	linkNormal linkType = iota
+	linkImg
+	linkDeferredFootnote
+	linkInlineFootnote
+)
+
+func isReferenceStyleLink(data []byte, pos int, t linkType) bool {
+	if t == linkDeferredFootnote {
+		return false
+	}
+	return pos < len(data)-1 && data[pos] == '[' && data[pos+1] != '^'
+}
+
+func maybeImage(p *Markdown, data []byte, offset int) (int, *Node) {
+	if offset < len(data)-1 && data[offset+1] == '[' {
+		return link(p, data, offset)
+	}
+	return 0, nil
+}
+
+func maybeInlineFootnote(p *Markdown, data []byte, offset int) (int, *Node) {
+	if offset < len(data)-1 && data[offset+1] == '[' {
+		return link(p, data, offset)
+	}
+	return 0, nil
+}
+
+// '[': parse a link or an image or a footnote
+func link(p *Markdown, data []byte, offset int) (int, *Node) {
+	// no links allowed inside regular links, footnote, and deferred footnotes
+	if p.insideLink && (offset > 0 && data[offset-1] == '[' || len(data)-1 > offset && data[offset+1] == '^') {
+		return 0, nil
+	}
+
+	var t linkType
+	switch {
+	// special case: ![^text] == deferred footnote (that follows something with
+	// an exclamation point)
+	case p.extensions&Footnotes != 0 && len(data)-1 > offset && data[offset+1] == '^':
+		t = linkDeferredFootnote
+	// ![alt] == image
+	case offset >= 0 && data[offset] == '!':
+		t = linkImg
+		offset++
+	// ^[text] == inline footnote
+	// [^refId] == deferred footnote
+	case p.extensions&Footnotes != 0:
+		if offset >= 0 && data[offset] == '^' {
+			t = linkInlineFootnote
+			offset++
+		} else if len(data)-1 > offset && data[offset+1] == '^' {
+			t = linkDeferredFootnote
+		}
+	// [text] == regular link
+	default:
+		t = linkNormal
+	}
+
+	data = data[offset:]
+
+	var (
+		i                       = 1
+		noteID                  int
+		title, link, altContent []byte
+		textHasNl               = false
+	)
+
+	if t == linkDeferredFootnote {
+		i++
+	}
+
+	// look for the matching closing bracket
+	for level := 1; level > 0 && i < len(data); i++ {
+		switch {
+		case data[i] == '\n':
+			textHasNl = true
+
+		case isBackslashEscaped(data, i):
+			continue
+
+		case data[i] == '[':
+			level++
+
+		case data[i] == ']':
+			level--
+			if level <= 0 {
+				i-- // compensate for extra i++ in for loop
+			}
+		}
+	}
+
+	if i >= len(data) {
+		return 0, nil
+	}
+
+	txtE := i
+	i++
+	var footnoteNode *Node
+
+	// skip any amount of whitespace or newline
+	// (this is much more lax than original markdown syntax)
+	for i < len(data) && isspace(data[i]) {
+		i++
+	}
+
+	// inline style link
+	switch {
+	case i < len(data) && data[i] == '(':
+		// skip initial whitespace
+		i++
+
+		for i < len(data) && isspace(data[i]) {
+			i++
+		}
+
+		linkB := i
+
+		// look for link end: ' " )
+	findlinkend:
+		for i < len(data) {
+			switch {
+			case data[i] == '\\':
+				i += 2
+
+			case data[i] == ')' || data[i] == '\'' || data[i] == '"':
+				break findlinkend
+
+			default:
+				i++
+			}
+		}
+
+		if i >= len(data) {
+			return 0, nil
+		}
+		linkE := i
+
+		// look for title end if present
+		titleB, titleE := 0, 0
+		if data[i] == '\'' || data[i] == '"' {
+			i++
+			titleB = i
+
+		findtitleend:
+			for i < len(data) {
+				switch {
+				case data[i] == '\\':
+					i += 2
+
+				case data[i] == ')':
+					break findtitleend
+
+				default:
+					i++
+				}
+			}
+
+			if i >= len(data) {
+				return 0, nil
+			}
+
+			// skip whitespace after title
+			titleE = i - 1
+			for titleE > titleB && isspace(data[titleE]) {
+				titleE--
+			}
+
+			// check for closing quote presence
+			if data[titleE] != '\'' && data[titleE] != '"' {
+				titleB, titleE = 0, 0
+				linkE = i
+			}
+		}
+
+		// remove whitespace at the end of the link
+		for linkE > linkB && isspace(data[linkE-1]) {
+			linkE--
+		}
+
+		// remove optional angle brackets around the link
+		if data[linkB] == '<' {
+			linkB++
+		}
+		if data[linkE-1] == '>' {
+			linkE--
+		}
+
+		// build escaped link and title
+		if linkE > linkB {
+			link = data[linkB:linkE]
+		}
+
+		if titleE > titleB {
+			title = data[titleB:titleE]
+		}
+
+		i++
+
+	// reference style link
+	case isReferenceStyleLink(data, i, t):
+		var id []byte
+		altContentConsidered := false
+
+		// look for the id
+		i++
+		linkB := i
+		for i < len(data) && data[i] != ']' {
+			i++
+		}
+		if i >= len(data) {
+			return 0, nil
+		}
+		linkE := i
+
+		// find the reference
+		if linkB == linkE {
+			if textHasNl {
+				var b bytes.Buffer
+
+				for j := 1; j < txtE; j++ {
+					switch {
+					case data[j] != '\n':
+						b.WriteByte(data[j])
+					case data[j-1] != ' ':
+						b.WriteByte(' ')
+					}
+				}
+
+				id = b.Bytes()
+			} else {
+				id = data[1:txtE]
+				altContentConsidered = true
+			}
+		} else {
+			id = data[linkB:linkE]
+		}
+
+		// find the reference with matching id
+		lr, ok := p.getRef(string(id))
+		if !ok {
+			return 0, nil
+		}
+
+		// keep link and title from reference
+		link = lr.link
+		title = lr.title
+		if altContentConsidered {
+			altContent = lr.text
+		}
+		i++
+
+	// shortcut reference style link or reference or inline footnote
+	default:
+		var id []byte
+
+		// craft the id
+		if textHasNl {
+			var b bytes.Buffer
+
+			for j := 1; j < txtE; j++ {
+				switch {
+				case data[j] != '\n':
+					b.WriteByte(data[j])
+				case data[j-1] != ' ':
+					b.WriteByte(' ')
+				}
+			}
+
+			id = b.Bytes()
+		} else {
+			if t == linkDeferredFootnote {
+				id = data[2:txtE] // get rid of the ^
+			} else {
+				id = data[1:txtE]
+			}
+		}
+
+		footnoteNode = NewNode(Item)
+		if t == linkInlineFootnote {
+			// create a new reference
+			noteID = len(p.notes) + 1
+
+			var fragment []byte
+			if len(id) > 0 {
+				if len(id) < 16 {
+					fragment = make([]byte, len(id))
+				} else {
+					fragment = make([]byte, 16)
+				}
+				copy(fragment, slugify(id))
+			} else {
+				fragment = append([]byte("footnote-"), []byte(strconv.Itoa(noteID))...)
+			}
+
+			ref := &reference{
+				noteID:   noteID,
+				hasBlock: false,
+				link:     fragment,
+				title:    id,
+				footnote: footnoteNode,
+			}
+
+			p.notes = append(p.notes, ref)
+
+			link = ref.link
+			title = ref.title
+		} else {
+			// find the reference with matching id
+			lr, ok := p.getRef(string(id))
+			if !ok {
+				return 0, nil
+			}
+
+			if t == linkDeferredFootnote {
+				lr.noteID = len(p.notes) + 1
+				lr.footnote = footnoteNode
+				p.notes = append(p.notes, lr)
+			}
+
+			// keep link and title from reference
+			link = lr.link
+			// if inline footnote, title == footnote contents
+			title = lr.title
+			noteID = lr.noteID
+		}
+
+		// rewind the whitespace
+		i = txtE + 1
+	}
+
+	var uLink []byte
+	if t == linkNormal || t == linkImg {
+		if len(link) > 0 {
+			var uLinkBuf bytes.Buffer
+			unescapeText(&uLinkBuf, link)
+			uLink = uLinkBuf.Bytes()
+		}
+
+		// links need something to click on and somewhere to go
+		if len(uLink) == 0 || (t == linkNormal && txtE <= 1) {
+			return 0, nil
+		}
+	}
+
+	// call the relevant rendering function
+	var linkNode *Node
+	switch t {
+	case linkNormal:
+		linkNode = NewNode(Link)
+		linkNode.Destination = normalizeURI(uLink)
+		linkNode.Title = title
+		if len(altContent) > 0 {
+			linkNode.AppendChild(text(altContent))
+		} else {
+			// links cannot contain other links, so turn off link parsing
+			// temporarily and recurse
+			insideLink := p.insideLink
+			p.insideLink = true
+			p.inline(linkNode, data[1:txtE])
+			p.insideLink = insideLink
+		}
+
+	case linkImg:
+		linkNode = NewNode(Image)
+		linkNode.Destination = uLink
+		linkNode.Title = title
+		linkNode.AppendChild(text(data[1:txtE]))
+		i++
+
+	case linkInlineFootnote, linkDeferredFootnote:
+		linkNode = NewNode(Link)
+		linkNode.Destination = link
+		linkNode.Title = title
+		linkNode.NoteID = noteID
+		linkNode.Footnote = footnoteNode
+		if t == linkInlineFootnote {
+			i++
+		}
+
+	default:
+		return 0, nil
+	}
+
+	return i, linkNode
+}
+
+func (p *Markdown) inlineHTMLComment(data []byte) int {
+	if len(data) < 5 {
+		return 0
+	}
+	if data[0] != '<' || data[1] != '!' || data[2] != '-' || data[3] != '-' {
+		return 0
+	}
+	i := 5
+	// scan for an end-of-comment marker, across lines if necessary
+	for i < len(data) && !(data[i-2] == '-' && data[i-1] == '-' && data[i] == '>') {
+		i++
+	}
+	// no end-of-comment marker
+	if i >= len(data) {
+		return 0
+	}
+	return i + 1
+}
+
+func stripMailto(link []byte) []byte {
+	if bytes.HasPrefix(link, []byte("mailto://")) {
+		return link[9:]
+	} else if bytes.HasPrefix(link, []byte("mailto:")) {
+		return link[7:]
+	} else {
+		return link
+	}
+}
+
+// autolinkType specifies a kind of autolink that gets detected.
+type autolinkType int
+
+// These are the possible flag values for the autolink renderer.
+const (
+	notAutolink autolinkType = iota
+	normalAutolink
+	emailAutolink
+)
+
+// '<' when tags or autolinks are allowed
+func leftAngle(p *Markdown, data []byte, offset int) (int, *Node) {
+	data = data[offset:]
+	altype, end := tagLength(data)
+	if size := p.inlineHTMLComment(data); size > 0 {
+		end = size
+	}
+	if end > 2 {
+		if altype != notAutolink {
+			var uLink bytes.Buffer
+			unescapeText(&uLink, data[1:end+1-2])
+			if uLink.Len() > 0 {
+				link := uLink.Bytes()
+				node := NewNode(Link)
+				node.Destination = link
+				if altype == emailAutolink {
+					node.Destination = append([]byte("mailto:"), link...)
+				}
+				node.AppendChild(text(stripMailto(link)))
+				return end, node
+			}
+		} else {
+			htmlTag := NewNode(HTMLSpan)
+			htmlTag.Literal = data[:end]
+			return end, htmlTag
+		}
+	}
+
+	return end, nil
+}
+
+// '\\' backslash escape
+var escapeChars = []byte("\\`*_{}[]()#+-.!:|&<>~")
+
+func escape(p *Markdown, data []byte, offset int) (int, *Node) {
+	data = data[offset:]
+
+	if len(data) > 1 {
+		if p.extensions&BackslashLineBreak != 0 && data[1] == '\n' {
+			return 2, NewNode(Hardbreak)
+		}
+		if bytes.IndexByte(escapeChars, data[1]) < 0 {
+			return 0, nil
+		}
+
+		return 2, text(data[1:2])
+	}
+
+	return 2, nil
+}
+
+func unescapeText(ob *bytes.Buffer, src []byte) {
+	i := 0
+	for i < len(src) {
+		org := i
+		for i < len(src) && src[i] != '\\' {
+			i++
+		}
+
+		if i > org {
+			ob.Write(src[org:i])
+		}
+
+		if i+1 >= len(src) {
+			break
+		}
+
+		ob.WriteByte(src[i+1])
+		i += 2
+	}
+}
+
+// '&' escaped when it doesn't belong to an entity
+// valid entities are assumed to be anything matching &#?[A-Za-z0-9]+;
+func entity(p *Markdown, data []byte, offset int) (int, *Node) {
+	data = data[offset:]
+
+	end := 1
+
+	if end < len(data) && data[end] == '#' {
+		end++
+	}
+
+	for end < len(data) && isalnum(data[end]) {
+		end++
+	}
+
+	if end < len(data) && data[end] == ';' {
+		end++ // real entity
+	} else {
+		return 0, nil // lone '&'
+	}
+
+	ent := data[:end]
+	// undo &amp; escaping or it will be converted to &amp;amp; by another
+	// escaper in the renderer
+	if bytes.Equal(ent, []byte("&amp;")) {
+		ent = []byte{'&'}
+	}
+
+	return end, text(ent)
+}
+
+func linkEndsWithEntity(data []byte, linkEnd int) bool {
+	entityRanges := htmlEntityRe.FindAllIndex(data[:linkEnd], -1)
+	return entityRanges != nil && entityRanges[len(entityRanges)-1][1] == linkEnd
+}
+
+// hasPrefixCaseInsensitive is a custom implementation of
+//     strings.HasPrefix(strings.ToLower(s), prefix)
+// we rolled our own because ToLower pulls in a huge machinery of lowercasing
+// anything from Unicode and that's very slow. Since this func will only be
+// used on ASCII protocol prefixes, we can take shortcuts.
+func hasPrefixCaseInsensitive(s, prefix []byte) bool {
+	if len(s) < len(prefix) {
+		return false
+	}
+	delta := byte('a' - 'A')
+	for i, b := range prefix {
+		if b != s[i] && b != s[i]+delta {
+			return false
+		}
+	}
+	return true
+}
+
+var protocolPrefixes = [][]byte{
+	[]byte("http://"),
+	[]byte("https://"),
+	[]byte("ftp://"),
+	[]byte("file://"),
+	[]byte("mailto:"),
+}
+
+const shortestPrefix = 6 // len("ftp://"), the shortest of the above
+
+func maybeAutoLink(p *Markdown, data []byte, offset int) (int, *Node) {
+	// quick check to rule out most false hits
+	if p.insideLink || len(data) < offset+shortestPrefix {
+		return 0, nil
+	}
+	for _, prefix := range protocolPrefixes {
+		endOfHead := offset + 8 // 8 is the len() of the longest prefix
+		if endOfHead > len(data) {
+			endOfHead = len(data)
+		}
+		if hasPrefixCaseInsensitive(data[offset:endOfHead], prefix) {
+			return autoLink(p, data, offset)
+		}
+	}
+	return 0, nil
+}
+
+func autoLink(p *Markdown, data []byte, offset int) (int, *Node) {
+	// Now a more expensive check to see if we're not inside an anchor element
+	anchorStart := offset
+	offsetFromAnchor := 0
+	for anchorStart > 0 && data[anchorStart] != '<' {
+		anchorStart--
+		offsetFromAnchor++
+	}
+
+	anchorStr := anchorRe.Find(data[anchorStart:])
+	if anchorStr != nil {
+		anchorClose := NewNode(HTMLSpan)
+		anchorClose.Literal = anchorStr[offsetFromAnchor:]
+		return len(anchorStr) - offsetFromAnchor, anchorClose
+	}
+
+	// scan backward for a word boundary
+	rewind := 0
+	for offset-rewind > 0 && rewind <= 7 && isletter(data[offset-rewind-1]) {
+		rewind++
+	}
+	if rewind > 6 { // longest supported protocol is "mailto" which has 6 letters
+		return 0, nil
+	}
+
+	origData := data
+	data = data[offset-rewind:]
+
+	if !isSafeLink(data) {
+		return 0, nil
+	}
+
+	linkEnd := 0
+	for linkEnd < len(data) && !isEndOfLink(data[linkEnd]) {
+		linkEnd++
+	}
+
+	// Skip punctuation at the end of the link
+	if (data[linkEnd-1] == '.' || data[linkEnd-1] == ',') && data[linkEnd-2] != '\\' {
+		linkEnd--
+	}
+
+	// But don't skip semicolon if it's a part of escaped entity:
+	if data[linkEnd-1] == ';' && data[linkEnd-2] != '\\' && !linkEndsWithEntity(data, linkEnd) {
+		linkEnd--
+	}
+
+	// See if the link finishes with a punctuation sign that can be closed.
+	var copen byte
+	switch data[linkEnd-1] {
+	case '"':
+		copen = '"'
+	case '\'':
+		copen = '\''
+	case ')':
+		copen = '('
+	case ']':
+		copen = '['
+	case '}':
+		copen = '{'
+	default:
+		copen = 0
+	}
+
+	if copen != 0 {
+		bufEnd := offset - rewind + linkEnd - 2
+
+		openDelim := 1
+
+		/* Try to close the final punctuation sign in this same line;
+		 * if we managed to close it outside of the URL, that means that it's
+		 * not part of the URL. If it closes inside the URL, that means it
+		 * is part of the URL.
+		 *
+		 * Examples:
+		 *
+		 *      foo http://www.pokemon.com/Pikachu_(Electric) bar
+		 *              => http://www.pokemon.com/Pikachu_(Electric)
+		 *
+		 *      foo (http://www.pokemon.com/Pikachu_(Electric)) bar
+		 *              => http://www.pokemon.com/Pikachu_(Electric)
+		 *
+		 *      foo http://www.pokemon.com/Pikachu_(Electric)) bar
+		 *              => http://www.pokemon.com/Pikachu_(Electric))
+		 *
+		 *      (foo http://www.pokemon.com/Pikachu_(Electric)) bar
+		 *              => foo http://www.pokemon.com/Pikachu_(Electric)
+		 */
+
+		for bufEnd >= 0 && origData[bufEnd] != '\n' && openDelim != 0 {
+			if origData[bufEnd] == data[linkEnd-1] {
+				openDelim++
+			}
+
+			if origData[bufEnd] == copen {
+				openDelim--
+			}
+
+			bufEnd--
+		}
+
+		if openDelim == 0 {
+			linkEnd--
+		}
+	}
+
+	var uLink bytes.Buffer
+	unescapeText(&uLink, data[:linkEnd])
+
+	if uLink.Len() > 0 {
+		node := NewNode(Link)
+		node.Destination = uLink.Bytes()
+		node.AppendChild(text(uLink.Bytes()))
+		return linkEnd, node
+	}
+
+	return linkEnd, nil
+}
+
+func isEndOfLink(char byte) bool {
+	return isspace(char) || char == '<'
+}
+
+var validUris = [][]byte{[]byte("http://"), []byte("https://"), []byte("ftp://"), []byte("mailto://")}
+var validPaths = [][]byte{[]byte("/"), []byte("./"), []byte("../")}
+
+func isSafeLink(link []byte) bool {
+	for _, path := range validPaths {
+		if len(link) >= len(path) && bytes.Equal(link[:len(path)], path) {
+			if len(link) == len(path) {
+				return true
+			} else if isalnum(link[len(path)]) {
+				return true
+			}
+		}
+	}
+
+	for _, prefix := range validUris {
+		// TODO: handle unicode here
+		// case-insensitive prefix test
+		if len(link) > len(prefix) && bytes.Equal(bytes.ToLower(link[:len(prefix)]), prefix) && isalnum(link[len(prefix)]) {
+			return true
+		}
+	}
+
+	return false
+}
+
+// return the length of the given tag, or 0 is it's not valid
+func tagLength(data []byte) (autolink autolinkType, end int) {
+	var i, j int
+
+	// a valid tag can't be shorter than 3 chars
+	if len(data) < 3 {
+		return notAutolink, 0
+	}
+
+	// begins with a '<' optionally followed by '/', followed by letter or number
+	if data[0] != '<' {
+		return notAutolink, 0
+	}
+	if data[1] == '/' {
+		i = 2
+	} else {
+		i = 1
+	}
+
+	if !isalnum(data[i]) {
+		return notAutolink, 0
+	}
+
+	// scheme test
+	autolink = notAutolink
+
+	// try to find the beginning of an URI
+	for i < len(data) && (isalnum(data[i]) || data[i] == '.' || data[i] == '+' || data[i] == '-') {
+		i++
+	}
+
+	if i > 1 && i < len(data) && data[i] == '@' {
+		if j = isMailtoAutoLink(data[i:]); j != 0 {
+			return emailAutolink, i + j
+		}
+	}
+
+	if i > 2 && i < len(data) && data[i] == ':' {
+		autolink = normalAutolink
+		i++
+	}
+
+	// complete autolink test: no whitespace or ' or "
+	switch {
+	case i >= len(data):
+		autolink = notAutolink
+	case autolink != notAutolink:
+		j = i
+
+		for i < len(data) {
+			if data[i] == '\\' {
+				i += 2
+			} else if data[i] == '>' || data[i] == '\'' || data[i] == '"' || isspace(data[i]) {
+				break
+			} else {
+				i++
+			}
+
+		}
+
+		if i >= len(data) {
+			return autolink, 0
+		}
+		if i > j && data[i] == '>' {
+			return autolink, i + 1
+		}
+
+		// one of the forbidden chars has been found
+		autolink = notAutolink
+	}
+	i += bytes.IndexByte(data[i:], '>')
+	if i < 0 {
+		return autolink, 0
+	}
+	return autolink, i + 1
+}
+
+// look for the address part of a mail autolink and '>'
+// this is less strict than the original markdown e-mail address matching
+func isMailtoAutoLink(data []byte) int {
+	nb := 0
+
+	// address is assumed to be: [-@._a-zA-Z0-9]+ with exactly one '@'
+	for i := 0; i < len(data); i++ {
+		if isalnum(data[i]) {
+			continue
+		}
+
+		switch data[i] {
+		case '@':
+			nb++
+
+		case '-', '.', '_':
+			break
+
+		case '>':
+			if nb == 1 {
+				return i + 1
+			}
+			return 0
+		default:
+			return 0
+		}
+	}
+
+	return 0
+}
+
+// look for the next emph char, skipping other constructs
+func helperFindEmphChar(data []byte, c byte) int {
+	i := 0
+
+	for i < len(data) {
+		for i < len(data) && data[i] != c && data[i] != '`' && data[i] != '[' {
+			i++
+		}
+		if i >= len(data) {
+			return 0
+		}
+		// do not count escaped chars
+		if i != 0 && data[i-1] == '\\' {
+			i++
+			continue
+		}
+		if data[i] == c {
+			return i
+		}
+
+		if data[i] == '`' {
+			// skip a code span
+			tmpI := 0
+			i++
+			for i < len(data) && data[i] != '`' {
+				if tmpI == 0 && data[i] == c {
+					tmpI = i
+				}
+				i++
+			}
+			if i >= len(data) {
+				return tmpI
+			}
+			i++
+		} else if data[i] == '[' {
+			// skip a link
+			tmpI := 0
+			i++
+			for i < len(data) && data[i] != ']' {
+				if tmpI == 0 && data[i] == c {
+					tmpI = i
+				}
+				i++
+			}
+			i++
+			for i < len(data) && (data[i] == ' ' || data[i] == '\n') {
+				i++
+			}
+			if i >= len(data) {
+				return tmpI
+			}
+			if data[i] != '[' && data[i] != '(' { // not a link
+				if tmpI > 0 {
+					return tmpI
+				}
+				continue
+			}
+			cc := data[i]
+			i++
+			for i < len(data) && data[i] != cc {
+				if tmpI == 0 && data[i] == c {
+					return i
+				}
+				i++
+			}
+			if i >= len(data) {
+				return tmpI
+			}
+			i++
+		}
+	}
+	return 0
+}
+
+func helperEmphasis(p *Markdown, data []byte, c byte) (int, *Node) {
+	i := 0
+
+	// skip one symbol if coming from emph3
+	if len(data) > 1 && data[0] == c && data[1] == c {
+		i = 1
+	}
+
+	for i < len(data) {
+		length := helperFindEmphChar(data[i:], c)
+		if length == 0 {
+			return 0, nil
+		}
+		i += length
+		if i >= len(data) {
+			return 0, nil
+		}
+
+		if i+1 < len(data) && data[i+1] == c {
+			i++
+			continue
+		}
+
+		if data[i] == c && !isspace(data[i-1]) {
+
+			if p.extensions&NoIntraEmphasis != 0 {
+				if !(i+1 == len(data) || isspace(data[i+1]) || ispunct(data[i+1])) {
+					continue
+				}
+			}
+
+			emph := NewNode(Emph)
+			p.inline(emph, data[:i])
+			return i + 1, emph
+		}
+	}
+
+	return 0, nil
+}
+
+func helperDoubleEmphasis(p *Markdown, data []byte, c byte) (int, *Node) {
+	i := 0
+
+	for i < len(data) {
+		length := helperFindEmphChar(data[i:], c)
+		if length == 0 {
+			return 0, nil
+		}
+		i += length
+
+		if i+1 < len(data) && data[i] == c && data[i+1] == c && i > 0 && !isspace(data[i-1]) {
+			nodeType := Strong
+			if c == '~' {
+				nodeType = Del
+			}
+			node := NewNode(nodeType)
+			p.inline(node, data[:i])
+			return i + 2, node
+		}
+		i++
+	}
+	return 0, nil
+}
+
+func helperTripleEmphasis(p *Markdown, data []byte, offset int, c byte) (int, *Node) {
+	i := 0
+	origData := data
+	data = data[offset:]
+
+	for i < len(data) {
+		length := helperFindEmphChar(data[i:], c)
+		if length == 0 {
+			return 0, nil
+		}
+		i += length
+
+		// skip whitespace preceded symbols
+		if data[i] != c || isspace(data[i-1]) {
+			continue
+		}
+
+		switch {
+		case i+2 < len(data) && data[i+1] == c && data[i+2] == c:
+			// triple symbol found
+			strong := NewNode(Strong)
+			em := NewNode(Emph)
+			strong.AppendChild(em)
+			p.inline(em, data[:i])
+			return i + 3, strong
+		case (i+1 < len(data) && data[i+1] == c):
+			// double symbol found, hand over to emph1
+			length, node := helperEmphasis(p, origData[offset-2:], c)
+			if length == 0 {
+				return 0, nil
+			}
+			return length - 2, node
+		default:
+			// single symbol found, hand over to emph2
+			length, node := helperDoubleEmphasis(p, origData[offset-1:], c)
+			if length == 0 {
+				return 0, nil
+			}
+			return length - 1, node
+		}
+	}
+	return 0, nil
+}
+
+func text(s []byte) *Node {
+	node := NewNode(Text)
+	node.Literal = s
+	return node
+}
+
+func normalizeURI(s []byte) []byte {
+	return s // TODO: implement
+}
diff --git a/vendor/github.com/russross/blackfriday/v2/markdown.go b/vendor/github.com/russross/blackfriday/v2/markdown.go
new file mode 100644
index 000000000000..58d2e4538c62
--- /dev/null
+++ b/vendor/github.com/russross/blackfriday/v2/markdown.go
@@ -0,0 +1,950 @@
+// Blackfriday Markdown Processor
+// Available at http://github.com/russross/blackfriday
+//
+// Copyright © 2011 Russ Ross <russ@russross.com>.
+// Distributed under the Simplified BSD License.
+// See README.md for details.
+
+package blackfriday
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"strings"
+	"unicode/utf8"
+)
+
+//
+// Markdown parsing and processing
+//
+
+// Version string of the package. Appears in the rendered document when
+// CompletePage flag is on.
+const Version = "2.0"
+
+// Extensions is a bitwise or'ed collection of enabled Blackfriday's
+// extensions.
+type Extensions int
+
+// These are the supported markdown parsing extensions.
+// OR these values together to select multiple extensions.
+const (
+	NoExtensions           Extensions = 0
+	NoIntraEmphasis        Extensions = 1 << iota // Ignore emphasis markers inside words
+	Tables                                        // Render tables
+	FencedCode                                    // Render fenced code blocks
+	Autolink                                      // Detect embedded URLs that are not explicitly marked
+	Strikethrough                                 // Strikethrough text using ~~test~~
+	LaxHTMLBlocks                                 // Loosen up HTML block parsing rules
+	SpaceHeadings                                 // Be strict about prefix heading rules
+	HardLineBreak                                 // Translate newlines into line breaks
+	TabSizeEight                                  // Expand tabs to eight spaces instead of four
+	Footnotes                                     // Pandoc-style footnotes
+	NoEmptyLineBeforeBlock                        // No need to insert an empty line to start a (code, quote, ordered list, unordered list) block
+	HeadingIDs                                    // specify heading IDs  with {#id}
+	Titleblock                                    // Titleblock ala pandoc
+	AutoHeadingIDs                                // Create the heading ID from the text
+	BackslashLineBreak                            // Translate trailing backslashes into line breaks
+	DefinitionLists                               // Render definition lists
+
+	CommonHTMLFlags HTMLFlags = UseXHTML | Smartypants |
+		SmartypantsFractions | SmartypantsDashes | SmartypantsLatexDashes
+
+	CommonExtensions Extensions = NoIntraEmphasis | Tables | FencedCode |
+		Autolink | Strikethrough | SpaceHeadings | HeadingIDs |
+		BackslashLineBreak | DefinitionLists
+)
+
+// ListType contains bitwise or'ed flags for list and list item objects.
+type ListType int
+
+// These are the possible flag values for the ListItem renderer.
+// Multiple flag values may be ORed together.
+// These are mostly of interest if you are writing a new output format.
+const (
+	ListTypeOrdered ListType = 1 << iota
+	ListTypeDefinition
+	ListTypeTerm
+
+	ListItemContainsBlock
+	ListItemBeginningOfList // TODO: figure out if this is of any use now
+	ListItemEndOfList
+)
+
+// CellAlignFlags holds a type of alignment in a table cell.
+type CellAlignFlags int
+
+// These are the possible flag values for the table cell renderer.
+// Only a single one of these values will be used; they are not ORed together.
+// These are mostly of interest if you are writing a new output format.
+const (
+	TableAlignmentLeft CellAlignFlags = 1 << iota
+	TableAlignmentRight
+	TableAlignmentCenter = (TableAlignmentLeft | TableAlignmentRight)
+)
+
+// The size of a tab stop.
+const (
+	TabSizeDefault = 4
+	TabSizeDouble  = 8
+)
+
+// blockTags is a set of tags that are recognized as HTML block tags.
+// Any of these can be included in markdown text without special escaping.
+var blockTags = map[string]struct{}{
+	"blockquote": {},
+	"del":        {},
+	"div":        {},
+	"dl":         {},
+	"fieldset":   {},
+	"form":       {},
+	"h1":         {},
+	"h2":         {},
+	"h3":         {},
+	"h4":         {},
+	"h5":         {},
+	"h6":         {},
+	"iframe":     {},
+	"ins":        {},
+	"math":       {},
+	"noscript":   {},
+	"ol":         {},
+	"pre":        {},
+	"p":          {},
+	"script":     {},
+	"style":      {},
+	"table":      {},
+	"ul":         {},
+
+	// HTML5
+	"address":    {},
+	"article":    {},
+	"aside":      {},
+	"canvas":     {},
+	"figcaption": {},
+	"figure":     {},
+	"footer":     {},
+	"header":     {},
+	"hgroup":     {},
+	"main":       {},
+	"nav":        {},
+	"output":     {},
+	"progress":   {},
+	"section":    {},
+	"video":      {},
+}
+
+// Renderer is the rendering interface. This is mostly of interest if you are
+// implementing a new rendering format.
+//
+// Only an HTML implementation is provided in this repository, see the README
+// for external implementations.
+type Renderer interface {
+	// RenderNode is the main rendering method. It will be called once for
+	// every leaf node and twice for every non-leaf node (first with
+	// entering=true, then with entering=false). The method should write its
+	// rendition of the node to the supplied writer w.
+	RenderNode(w io.Writer, node *Node, entering bool) WalkStatus
+
+	// RenderHeader is a method that allows the renderer to produce some
+	// content preceding the main body of the output document. The header is
+	// understood in the broad sense here. For example, the default HTML
+	// renderer will write not only the HTML document preamble, but also the
+	// table of contents if it was requested.
+	//
+	// The method will be passed an entire document tree, in case a particular
+	// implementation needs to inspect it to produce output.
+	//
+	// The output should be written to the supplied writer w. If your
+	// implementation has no header to write, supply an empty implementation.
+	RenderHeader(w io.Writer, ast *Node)
+
+	// RenderFooter is a symmetric counterpart of RenderHeader.
+	RenderFooter(w io.Writer, ast *Node)
+}
+
+// Callback functions for inline parsing. One such function is defined
+// for each character that triggers a response when parsing inline data.
+type inlineParser func(p *Markdown, data []byte, offset int) (int, *Node)
+
+// Markdown is a type that holds extensions and the runtime state used by
+// Parse, and the renderer. You can not use it directly, construct it with New.
+type Markdown struct {
+	renderer          Renderer
+	referenceOverride ReferenceOverrideFunc
+	refs              map[string]*reference
+	inlineCallback    [256]inlineParser
+	extensions        Extensions
+	nesting           int
+	maxNesting        int
+	insideLink        bool
+
+	// Footnotes need to be ordered as well as available to quickly check for
+	// presence. If a ref is also a footnote, it's stored both in refs and here
+	// in notes. Slice is nil if footnotes not enabled.
+	notes []*reference
+
+	doc                  *Node
+	tip                  *Node // = doc
+	oldTip               *Node
+	lastMatchedContainer *Node // = doc
+	allClosed            bool
+}
+
+func (p *Markdown) getRef(refid string) (ref *reference, found bool) {
+	if p.referenceOverride != nil {
+		r, overridden := p.referenceOverride(refid)
+		if overridden {
+			if r == nil {
+				return nil, false
+			}
+			return &reference{
+				link:     []byte(r.Link),
+				title:    []byte(r.Title),
+				noteID:   0,
+				hasBlock: false,
+				text:     []byte(r.Text)}, true
+		}
+	}
+	// refs are case insensitive
+	ref, found = p.refs[strings.ToLower(refid)]
+	return ref, found
+}
+
+func (p *Markdown) finalize(block *Node) {
+	above := block.Parent
+	block.open = false
+	p.tip = above
+}
+
+func (p *Markdown) addChild(node NodeType, offset uint32) *Node {
+	return p.addExistingChild(NewNode(node), offset)
+}
+
+func (p *Markdown) addExistingChild(node *Node, offset uint32) *Node {
+	for !p.tip.canContain(node.Type) {
+		p.finalize(p.tip)
+	}
+	p.tip.AppendChild(node)
+	p.tip = node
+	return node
+}
+
+func (p *Markdown) closeUnmatchedBlocks() {
+	if !p.allClosed {
+		for p.oldTip != p.lastMatchedContainer {
+			parent := p.oldTip.Parent
+			p.finalize(p.oldTip)
+			p.oldTip = parent
+		}
+		p.allClosed = true
+	}
+}
+
+//
+//
+// Public interface
+//
+//
+
+// Reference represents the details of a link.
+// See the documentation in Options for more details on use-case.
+type Reference struct {
+	// Link is usually the URL the reference points to.
+	Link string
+	// Title is the alternate text describing the link in more detail.
+	Title string
+	// Text is the optional text to override the ref with if the syntax used was
+	// [refid][]
+	Text string
+}
+
+// ReferenceOverrideFunc is expected to be called with a reference string and
+// return either a valid Reference type that the reference string maps to or
+// nil. If overridden is false, the default reference logic will be executed.
+// See the documentation in Options for more details on use-case.
+type ReferenceOverrideFunc func(reference string) (ref *Reference, overridden bool)
+
+// New constructs a Markdown processor. You can use the same With* functions as
+// for Run() to customize parser's behavior and the renderer.
+func New(opts ...Option) *Markdown {
+	var p Markdown
+	for _, opt := range opts {
+		opt(&p)
+	}
+	p.refs = make(map[string]*reference)
+	p.maxNesting = 16
+	p.insideLink = false
+	docNode := NewNode(Document)
+	p.doc = docNode
+	p.tip = docNode
+	p.oldTip = docNode
+	p.lastMatchedContainer = docNode
+	p.allClosed = true
+	// register inline parsers
+	p.inlineCallback[' '] = maybeLineBreak
+	p.inlineCallback['*'] = emphasis
+	p.inlineCallback['_'] = emphasis
+	if p.extensions&Strikethrough != 0 {
+		p.inlineCallback['~'] = emphasis
+	}
+	p.inlineCallback['`'] = codeSpan
+	p.inlineCallback['\n'] = lineBreak
+	p.inlineCallback['['] = link
+	p.inlineCallback['<'] = leftAngle
+	p.inlineCallback['\\'] = escape
+	p.inlineCallback['&'] = entity
+	p.inlineCallback['!'] = maybeImage
+	p.inlineCallback['^'] = maybeInlineFootnote
+	if p.extensions&Autolink != 0 {
+		p.inlineCallback['h'] = maybeAutoLink
+		p.inlineCallback['m'] = maybeAutoLink
+		p.inlineCallback['f'] = maybeAutoLink
+		p.inlineCallback['H'] = maybeAutoLink
+		p.inlineCallback['M'] = maybeAutoLink
+		p.inlineCallback['F'] = maybeAutoLink
+	}
+	if p.extensions&Footnotes != 0 {
+		p.notes = make([]*reference, 0)
+	}
+	return &p
+}
+
+// Option customizes the Markdown processor's default behavior.
+type Option func(*Markdown)
+
+// WithRenderer allows you to override the default renderer.
+func WithRenderer(r Renderer) Option {
+	return func(p *Markdown) {
+		p.renderer = r
+	}
+}
+
+// WithExtensions allows you to pick some of the many extensions provided by
+// Blackfriday. You can bitwise OR them.
+func WithExtensions(e Extensions) Option {
+	return func(p *Markdown) {
+		p.extensions = e
+	}
+}
+
+// WithNoExtensions turns off all extensions and custom behavior.
+func WithNoExtensions() Option {
+	return func(p *Markdown) {
+		p.extensions = NoExtensions
+		p.renderer = NewHTMLRenderer(HTMLRendererParameters{
+			Flags: HTMLFlagsNone,
+		})
+	}
+}
+
+// WithRefOverride sets an optional function callback that is called every
+// time a reference is resolved.
+//
+// In Markdown, the link reference syntax can be made to resolve a link to
+// a reference instead of an inline URL, in one of the following ways:
+//
+//  * [link text][refid]
+//  * [refid][]
+//
+// Usually, the refid is defined at the bottom of the Markdown document. If
+// this override function is provided, the refid is passed to the override
+// function first, before consulting the defined refids at the bottom. If
+// the override function indicates an override did not occur, the refids at
+// the bottom will be used to fill in the link details.
+func WithRefOverride(o ReferenceOverrideFunc) Option {
+	return func(p *Markdown) {
+		p.referenceOverride = o
+	}
+}
+
+// Run is the main entry point to Blackfriday. It parses and renders a
+// block of markdown-encoded text.
+//
+// The simplest invocation of Run takes one argument, input:
+//     output := Run(input)
+// This will parse the input with CommonExtensions enabled and render it with
+// the default HTMLRenderer (with CommonHTMLFlags).
+//
+// Variadic arguments opts can customize the default behavior. Since Markdown
+// type does not contain exported fields, you can not use it directly. Instead,
+// use the With* functions. For example, this will call the most basic
+// functionality, with no extensions:
+//     output := Run(input, WithNoExtensions())
+//
+// You can use any number of With* arguments, even contradicting ones. They
+// will be applied in order of appearance and the latter will override the
+// former:
+//     output := Run(input, WithNoExtensions(), WithExtensions(exts),
+//         WithRenderer(yourRenderer))
+func Run(input []byte, opts ...Option) []byte {
+	r := NewHTMLRenderer(HTMLRendererParameters{
+		Flags: CommonHTMLFlags,
+	})
+	optList := []Option{WithRenderer(r), WithExtensions(CommonExtensions)}
+	optList = append(optList, opts...)
+	parser := New(optList...)
+	ast := parser.Parse(input)
+	var buf bytes.Buffer
+	parser.renderer.RenderHeader(&buf, ast)
+	ast.Walk(func(node *Node, entering bool) WalkStatus {
+		return parser.renderer.RenderNode(&buf, node, entering)
+	})
+	parser.renderer.RenderFooter(&buf, ast)
+	return buf.Bytes()
+}
+
+// Parse is an entry point to the parsing part of Blackfriday. It takes an
+// input markdown document and produces a syntax tree for its contents. This
+// tree can then be rendered with a default or custom renderer, or
+// analyzed/transformed by the caller to whatever non-standard needs they have.
+// The return value is the root node of the syntax tree.
+func (p *Markdown) Parse(input []byte) *Node {
+	p.block(input)
+	// Walk the tree and finish up some of unfinished blocks
+	for p.tip != nil {
+		p.finalize(p.tip)
+	}
+	// Walk the tree again and process inline markdown in each block
+	p.doc.Walk(func(node *Node, entering bool) WalkStatus {
+		if node.Type == Paragraph || node.Type == Heading || node.Type == TableCell {
+			p.inline(node, node.content)
+			node.content = nil
+		}
+		return GoToNext
+	})
+	p.parseRefsToAST()
+	return p.doc
+}
+
+func (p *Markdown) parseRefsToAST() {
+	if p.extensions&Footnotes == 0 || len(p.notes) == 0 {
+		return
+	}
+	p.tip = p.doc
+	block := p.addBlock(List, nil)
+	block.IsFootnotesList = true
+	block.ListFlags = ListTypeOrdered
+	flags := ListItemBeginningOfList
+	// Note: this loop is intentionally explicit, not range-form. This is
+	// because the body of the loop will append nested footnotes to p.notes and
+	// we need to process those late additions. Range form would only walk over
+	// the fixed initial set.
+	for i := 0; i < len(p.notes); i++ {
+		ref := p.notes[i]
+		p.addExistingChild(ref.footnote, 0)
+		block := ref.footnote
+		block.ListFlags = flags | ListTypeOrdered
+		block.RefLink = ref.link
+		if ref.hasBlock {
+			flags |= ListItemContainsBlock
+			p.block(ref.title)
+		} else {
+			p.inline(block, ref.title)
+		}
+		flags &^= ListItemBeginningOfList | ListItemContainsBlock
+	}
+	above := block.Parent
+	finalizeList(block)
+	p.tip = above
+	block.Walk(func(node *Node, entering bool) WalkStatus {
+		if node.Type == Paragraph || node.Type == Heading {
+			p.inline(node, node.content)
+			node.content = nil
+		}
+		return GoToNext
+	})
+}
+
+//
+// Link references
+//
+// This section implements support for references that (usually) appear
+// as footnotes in a document, and can be referenced anywhere in the document.
+// The basic format is:
+//
+//    [1]: http://www.google.com/ "Google"
+//    [2]: http://www.github.com/ "Github"
+//
+// Anywhere in the document, the reference can be linked by referring to its
+// label, i.e., 1 and 2 in this example, as in:
+//
+//    This library is hosted on [Github][2], a git hosting site.
+//
+// Actual footnotes as specified in Pandoc and supported by some other Markdown
+// libraries such as php-markdown are also taken care of. They look like this:
+//
+//    This sentence needs a bit of further explanation.[^note]
+//
+//    [^note]: This is the explanation.
+//
+// Footnotes should be placed at the end of the document in an ordered list.
+// Finally, there are inline footnotes such as:
+//
+//    Inline footnotes^[Also supported.] provide a quick inline explanation,
+//    but are rendered at the bottom of the document.
+//
+
+// reference holds all information necessary for a reference-style links or
+// footnotes.
+//
+// Consider this markdown with reference-style links:
+//
+//     [link][ref]
+//
+//     [ref]: /url/ "tooltip title"
+//
+// It will be ultimately converted to this HTML:
+//
+//     <p><a href=\"/url/\" title=\"title\">link</a></p>
+//
+// And a reference structure will be populated as follows:
+//
+//     p.refs["ref"] = &reference{
+//         link: "/url/",
+//         title: "tooltip title",
+//     }
+//
+// Alternatively, reference can contain information about a footnote. Consider
+// this markdown:
+//
+//     Text needing a footnote.[^a]
+//
+//     [^a]: This is the note
+//
+// A reference structure will be populated as follows:
+//
+//     p.refs["a"] = &reference{
+//         link: "a",
+//         title: "This is the note",
+//         noteID: <some positive int>,
+//     }
+//
+// TODO: As you can see, it begs for splitting into two dedicated structures
+// for refs and for footnotes.
+type reference struct {
+	link     []byte
+	title    []byte
+	noteID   int // 0 if not a footnote ref
+	hasBlock bool
+	footnote *Node // a link to the Item node within a list of footnotes
+
+	text []byte // only gets populated by refOverride feature with Reference.Text
+}
+
+func (r *reference) String() string {
+	return fmt.Sprintf("{link: %q, title: %q, text: %q, noteID: %d, hasBlock: %v}",
+		r.link, r.title, r.text, r.noteID, r.hasBlock)
+}
+
+// Check whether or not data starts with a reference link.
+// If so, it is parsed and stored in the list of references
+// (in the render struct).
+// Returns the number of bytes to skip to move past it,
+// or zero if the first line is not a reference.
+func isReference(p *Markdown, data []byte, tabSize int) int {
+	// up to 3 optional leading spaces
+	if len(data) < 4 {
+		return 0
+	}
+	i := 0
+	for i < 3 && data[i] == ' ' {
+		i++
+	}
+
+	noteID := 0
+
+	// id part: anything but a newline between brackets
+	if data[i] != '[' {
+		return 0
+	}
+	i++
+	if p.extensions&Footnotes != 0 {
+		if i < len(data) && data[i] == '^' {
+			// we can set it to anything here because the proper noteIds will
+			// be assigned later during the second pass. It just has to be != 0
+			noteID = 1
+			i++
+		}
+	}
+	idOffset := i
+	for i < len(data) && data[i] != '\n' && data[i] != '\r' && data[i] != ']' {
+		i++
+	}
+	if i >= len(data) || data[i] != ']' {
+		return 0
+	}
+	idEnd := i
+	// footnotes can have empty ID, like this: [^], but a reference can not be
+	// empty like this: []. Break early if it's not a footnote and there's no ID
+	if noteID == 0 && idOffset == idEnd {
+		return 0
+	}
+	// spacer: colon (space | tab)* newline? (space | tab)*
+	i++
+	if i >= len(data) || data[i] != ':' {
+		return 0
+	}
+	i++
+	for i < len(data) && (data[i] == ' ' || data[i] == '\t') {
+		i++
+	}
+	if i < len(data) && (data[i] == '\n' || data[i] == '\r') {
+		i++
+		if i < len(data) && data[i] == '\n' && data[i-1] == '\r' {
+			i++
+		}
+	}
+	for i < len(data) && (data[i] == ' ' || data[i] == '\t') {
+		i++
+	}
+	if i >= len(data) {
+		return 0
+	}
+
+	var (
+		linkOffset, linkEnd   int
+		titleOffset, titleEnd int
+		lineEnd               int
+		raw                   []byte
+		hasBlock              bool
+	)
+
+	if p.extensions&Footnotes != 0 && noteID != 0 {
+		linkOffset, linkEnd, raw, hasBlock = scanFootnote(p, data, i, tabSize)
+		lineEnd = linkEnd
+	} else {
+		linkOffset, linkEnd, titleOffset, titleEnd, lineEnd = scanLinkRef(p, data, i)
+	}
+	if lineEnd == 0 {
+		return 0
+	}
+
+	// a valid ref has been found
+
+	ref := &reference{
+		noteID:   noteID,
+		hasBlock: hasBlock,
+	}
+
+	if noteID > 0 {
+		// reusing the link field for the id since footnotes don't have links
+		ref.link = data[idOffset:idEnd]
+		// if footnote, it's not really a title, it's the contained text
+		ref.title = raw
+	} else {
+		ref.link = data[linkOffset:linkEnd]
+		ref.title = data[titleOffset:titleEnd]
+	}
+
+	// id matches are case-insensitive
+	id := string(bytes.ToLower(data[idOffset:idEnd]))
+
+	p.refs[id] = ref
+
+	return lineEnd
+}
+
+func scanLinkRef(p *Markdown, data []byte, i int) (linkOffset, linkEnd, titleOffset, titleEnd, lineEnd int) {
+	// link: whitespace-free sequence, optionally between angle brackets
+	if data[i] == '<' {
+		i++
+	}
+	linkOffset = i
+	for i < len(data) && data[i] != ' ' && data[i] != '\t' && data[i] != '\n' && data[i] != '\r' {
+		i++
+	}
+	linkEnd = i
+	if data[linkOffset] == '<' && data[linkEnd-1] == '>' {
+		linkOffset++
+		linkEnd--
+	}
+
+	// optional spacer: (space | tab)* (newline | '\'' | '"' | '(' )
+	for i < len(data) && (data[i] == ' ' || data[i] == '\t') {
+		i++
+	}
+	if i < len(data) && data[i] != '\n' && data[i] != '\r' && data[i] != '\'' && data[i] != '"' && data[i] != '(' {
+		return
+	}
+
+	// compute end-of-line
+	if i >= len(data) || data[i] == '\r' || data[i] == '\n' {
+		lineEnd = i
+	}
+	if i+1 < len(data) && data[i] == '\r' && data[i+1] == '\n' {
+		lineEnd++
+	}
+
+	// optional (space|tab)* spacer after a newline
+	if lineEnd > 0 {
+		i = lineEnd + 1
+		for i < len(data) && (data[i] == ' ' || data[i] == '\t') {
+			i++
+		}
+	}
+
+	// optional title: any non-newline sequence enclosed in '"() alone on its line
+	if i+1 < len(data) && (data[i] == '\'' || data[i] == '"' || data[i] == '(') {
+		i++
+		titleOffset = i
+
+		// look for EOL
+		for i < len(data) && data[i] != '\n' && data[i] != '\r' {
+			i++
+		}
+		if i+1 < len(data) && data[i] == '\n' && data[i+1] == '\r' {
+			titleEnd = i + 1
+		} else {
+			titleEnd = i
+		}
+
+		// step back
+		i--
+		for i > titleOffset && (data[i] == ' ' || data[i] == '\t') {
+			i--
+		}
+		if i > titleOffset && (data[i] == '\'' || data[i] == '"' || data[i] == ')') {
+			lineEnd = titleEnd
+			titleEnd = i
+		}
+	}
+
+	return
+}
+
+// The first bit of this logic is the same as Parser.listItem, but the rest
+// is much simpler. This function simply finds the entire block and shifts it
+// over by one tab if it is indeed a block (just returns the line if it's not).
+// blockEnd is the end of the section in the input buffer, and contents is the
+// extracted text that was shifted over one tab. It will need to be rendered at
+// the end of the document.
+func scanFootnote(p *Markdown, data []byte, i, indentSize int) (blockStart, blockEnd int, contents []byte, hasBlock bool) {
+	if i == 0 || len(data) == 0 {
+		return
+	}
+
+	// skip leading whitespace on first line
+	for i < len(data) && data[i] == ' ' {
+		i++
+	}
+
+	blockStart = i
+
+	// find the end of the line
+	blockEnd = i
+	for i < len(data) && data[i-1] != '\n' {
+		i++
+	}
+
+	// get working buffer
+	var raw bytes.Buffer
+
+	// put the first line into the working buffer
+	raw.Write(data[blockEnd:i])
+	blockEnd = i
+
+	// process the following lines
+	containsBlankLine := false
+
+gatherLines:
+	for blockEnd < len(data) {
+		i++
+
+		// find the end of this line
+		for i < len(data) && data[i-1] != '\n' {
+			i++
+		}
+
+		// if it is an empty line, guess that it is part of this item
+		// and move on to the next line
+		if p.isEmpty(data[blockEnd:i]) > 0 {
+			containsBlankLine = true
+			blockEnd = i
+			continue
+		}
+
+		n := 0
+		if n = isIndented(data[blockEnd:i], indentSize); n == 0 {
+			// this is the end of the block.
+			// we don't want to include this last line in the index.
+			break gatherLines
+		}
+
+		// if there were blank lines before this one, insert a new one now
+		if containsBlankLine {
+			raw.WriteByte('\n')
+			containsBlankLine = false
+		}
+
+		// get rid of that first tab, write to buffer
+		raw.Write(data[blockEnd+n : i])
+		hasBlock = true
+
+		blockEnd = i
+	}
+
+	if data[blockEnd-1] != '\n' {
+		raw.WriteByte('\n')
+	}
+
+	contents = raw.Bytes()
+
+	return
+}
+
+//
+//
+// Miscellaneous helper functions
+//
+//
+
+// Test if a character is a punctuation symbol.
+// Taken from a private function in regexp in the stdlib.
+func ispunct(c byte) bool {
+	for _, r := range []byte("!\"#$%&'()*+,-./:;<=>?@[\\]^_`{|}~") {
+		if c == r {
+			return true
+		}
+	}
+	return false
+}
+
+// Test if a character is a whitespace character.
+func isspace(c byte) bool {
+	return ishorizontalspace(c) || isverticalspace(c)
+}
+
+// Test if a character is a horizontal whitespace character.
+func ishorizontalspace(c byte) bool {
+	return c == ' ' || c == '\t'
+}
+
+// Test if a character is a vertical character.
+func isverticalspace(c byte) bool {
+	return c == '\n' || c == '\r' || c == '\f' || c == '\v'
+}
+
+// Test if a character is letter.
+func isletter(c byte) bool {
+	return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z')
+}
+
+// Test if a character is a letter or a digit.
+// TODO: check when this is looking for ASCII alnum and when it should use unicode
+func isalnum(c byte) bool {
+	return (c >= '0' && c <= '9') || isletter(c)
+}
+
+// Replace tab characters with spaces, aligning to the next TAB_SIZE column.
+// always ends output with a newline
+func expandTabs(out *bytes.Buffer, line []byte, tabSize int) {
+	// first, check for common cases: no tabs, or only tabs at beginning of line
+	i, prefix := 0, 0
+	slowcase := false
+	for i = 0; i < len(line); i++ {
+		if line[i] == '\t' {
+			if prefix == i {
+				prefix++
+			} else {
+				slowcase = true
+				break
+			}
+		}
+	}
+
+	// no need to decode runes if all tabs are at the beginning of the line
+	if !slowcase {
+		for i = 0; i < prefix*tabSize; i++ {
+			out.WriteByte(' ')
+		}
+		out.Write(line[prefix:])
+		return
+	}
+
+	// the slow case: we need to count runes to figure out how
+	// many spaces to insert for each tab
+	column := 0
+	i = 0
+	for i < len(line) {
+		start := i
+		for i < len(line) && line[i] != '\t' {
+			_, size := utf8.DecodeRune(line[i:])
+			i += size
+			column++
+		}
+
+		if i > start {
+			out.Write(line[start:i])
+		}
+
+		if i >= len(line) {
+			break
+		}
+
+		for {
+			out.WriteByte(' ')
+			column++
+			if column%tabSize == 0 {
+				break
+			}
+		}
+
+		i++
+	}
+}
+
+// Find if a line counts as indented or not.
+// Returns number of characters the indent is (0 = not indented).
+func isIndented(data []byte, indentSize int) int {
+	if len(data) == 0 {
+		return 0
+	}
+	if data[0] == '\t' {
+		return 1
+	}
+	if len(data) < indentSize {
+		return 0
+	}
+	for i := 0; i < indentSize; i++ {
+		if data[i] != ' ' {
+			return 0
+		}
+	}
+	return indentSize
+}
+
+// Create a url-safe slug for fragments
+func slugify(in []byte) []byte {
+	if len(in) == 0 {
+		return in
+	}
+	out := make([]byte, 0, len(in))
+	sym := false
+
+	for _, ch := range in {
+		if isalnum(ch) {
+			sym = false
+			out = append(out, ch)
+		} else if sym {
+			continue
+		} else {
+			out = append(out, '-')
+			sym = true
+		}
+	}
+	var a, b int
+	var ch byte
+	for a, ch = range out {
+		if ch != '-' {
+			break
+		}
+	}
+	for b = len(out) - 1; b > 0; b-- {
+		if out[b] != '-' {
+			break
+		}
+	}
+	return out[a : b+1]
+}
diff --git a/vendor/github.com/russross/blackfriday/v2/node.go b/vendor/github.com/russross/blackfriday/v2/node.go
new file mode 100644
index 000000000000..04e6050ceeae
--- /dev/null
+++ b/vendor/github.com/russross/blackfriday/v2/node.go
@@ -0,0 +1,360 @@
+package blackfriday
+
+import (
+	"bytes"
+	"fmt"
+)
+
+// NodeType specifies a type of a single node of a syntax tree. Usually one
+// node (and its type) corresponds to a single markdown feature, e.g. emphasis
+// or code block.
+type NodeType int
+
+// Constants for identifying different types of nodes. See NodeType.
+const (
+	Document NodeType = iota
+	BlockQuote
+	List
+	Item
+	Paragraph
+	Heading
+	HorizontalRule
+	Emph
+	Strong
+	Del
+	Link
+	Image
+	Text
+	HTMLBlock
+	CodeBlock
+	Softbreak
+	Hardbreak
+	Code
+	HTMLSpan
+	Table
+	TableCell
+	TableHead
+	TableBody
+	TableRow
+)
+
+var nodeTypeNames = []string{
+	Document:       "Document",
+	BlockQuote:     "BlockQuote",
+	List:           "List",
+	Item:           "Item",
+	Paragraph:      "Paragraph",
+	Heading:        "Heading",
+	HorizontalRule: "HorizontalRule",
+	Emph:           "Emph",
+	Strong:         "Strong",
+	Del:            "Del",
+	Link:           "Link",
+	Image:          "Image",
+	Text:           "Text",
+	HTMLBlock:      "HTMLBlock",
+	CodeBlock:      "CodeBlock",
+	Softbreak:      "Softbreak",
+	Hardbreak:      "Hardbreak",
+	Code:           "Code",
+	HTMLSpan:       "HTMLSpan",
+	Table:          "Table",
+	TableCell:      "TableCell",
+	TableHead:      "TableHead",
+	TableBody:      "TableBody",
+	TableRow:       "TableRow",
+}
+
+func (t NodeType) String() string {
+	return nodeTypeNames[t]
+}
+
+// ListData contains fields relevant to a List and Item node type.
+type ListData struct {
+	ListFlags       ListType
+	Tight           bool   // Skip <p>s around list item data if true
+	BulletChar      byte   // '*', '+' or '-' in bullet lists
+	Delimiter       byte   // '.' or ')' after the number in ordered lists
+	RefLink         []byte // If not nil, turns this list item into a footnote item and triggers different rendering
+	IsFootnotesList bool   // This is a list of footnotes
+}
+
+// LinkData contains fields relevant to a Link node type.
+type LinkData struct {
+	Destination []byte // Destination is what goes into a href
+	Title       []byte // Title is the tooltip thing that goes in a title attribute
+	NoteID      int    // NoteID contains a serial number of a footnote, zero if it's not a footnote
+	Footnote    *Node  // If it's a footnote, this is a direct link to the footnote Node. Otherwise nil.
+}
+
+// CodeBlockData contains fields relevant to a CodeBlock node type.
+type CodeBlockData struct {
+	IsFenced    bool   // Specifies whether it's a fenced code block or an indented one
+	Info        []byte // This holds the info string
+	FenceChar   byte
+	FenceLength int
+	FenceOffset int
+}
+
+// TableCellData contains fields relevant to a TableCell node type.
+type TableCellData struct {
+	IsHeader bool           // This tells if it's under the header row
+	Align    CellAlignFlags // This holds the value for align attribute
+}
+
+// HeadingData contains fields relevant to a Heading node type.
+type HeadingData struct {
+	Level        int    // This holds the heading level number
+	HeadingID    string // This might hold heading ID, if present
+	IsTitleblock bool   // Specifies whether it's a title block
+}
+
+// Node is a single element in the abstract syntax tree of the parsed document.
+// It holds connections to the structurally neighboring nodes and, for certain
+// types of nodes, additional information that might be needed when rendering.
+type Node struct {
+	Type       NodeType // Determines the type of the node
+	Parent     *Node    // Points to the parent
+	FirstChild *Node    // Points to the first child, if any
+	LastChild  *Node    // Points to the last child, if any
+	Prev       *Node    // Previous sibling; nil if it's the first child
+	Next       *Node    // Next sibling; nil if it's the last child
+
+	Literal []byte // Text contents of the leaf nodes
+
+	HeadingData   // Populated if Type is Heading
+	ListData      // Populated if Type is List
+	CodeBlockData // Populated if Type is CodeBlock
+	LinkData      // Populated if Type is Link
+	TableCellData // Populated if Type is TableCell
+
+	content []byte // Markdown content of the block nodes
+	open    bool   // Specifies an open block node that has not been finished to process yet
+}
+
+// NewNode allocates a node of a specified type.
+func NewNode(typ NodeType) *Node {
+	return &Node{
+		Type: typ,
+		open: true,
+	}
+}
+
+func (n *Node) String() string {
+	ellipsis := ""
+	snippet := n.Literal
+	if len(snippet) > 16 {
+		snippet = snippet[:16]
+		ellipsis = "..."
+	}
+	return fmt.Sprintf("%s: '%s%s'", n.Type, snippet, ellipsis)
+}
+
+// Unlink removes node 'n' from the tree.
+// It panics if the node is nil.
+func (n *Node) Unlink() {
+	if n.Prev != nil {
+		n.Prev.Next = n.Next
+	} else if n.Parent != nil {
+		n.Parent.FirstChild = n.Next
+	}
+	if n.Next != nil {
+		n.Next.Prev = n.Prev
+	} else if n.Parent != nil {
+		n.Parent.LastChild = n.Prev
+	}
+	n.Parent = nil
+	n.Next = nil
+	n.Prev = nil
+}
+
+// AppendChild adds a node 'child' as a child of 'n'.
+// It panics if either node is nil.
+func (n *Node) AppendChild(child *Node) {
+	child.Unlink()
+	child.Parent = n
+	if n.LastChild != nil {
+		n.LastChild.Next = child
+		child.Prev = n.LastChild
+		n.LastChild = child
+	} else {
+		n.FirstChild = child
+		n.LastChild = child
+	}
+}
+
+// InsertBefore inserts 'sibling' immediately before 'n'.
+// It panics if either node is nil.
+func (n *Node) InsertBefore(sibling *Node) {
+	sibling.Unlink()
+	sibling.Prev = n.Prev
+	if sibling.Prev != nil {
+		sibling.Prev.Next = sibling
+	}
+	sibling.Next = n
+	n.Prev = sibling
+	sibling.Parent = n.Parent
+	if sibling.Prev == nil {
+		sibling.Parent.FirstChild = sibling
+	}
+}
+
+// IsContainer returns true if 'n' can contain children.
+func (n *Node) IsContainer() bool {
+	switch n.Type {
+	case Document:
+		fallthrough
+	case BlockQuote:
+		fallthrough
+	case List:
+		fallthrough
+	case Item:
+		fallthrough
+	case Paragraph:
+		fallthrough
+	case Heading:
+		fallthrough
+	case Emph:
+		fallthrough
+	case Strong:
+		fallthrough
+	case Del:
+		fallthrough
+	case Link:
+		fallthrough
+	case Image:
+		fallthrough
+	case Table:
+		fallthrough
+	case TableHead:
+		fallthrough
+	case TableBody:
+		fallthrough
+	case TableRow:
+		fallthrough
+	case TableCell:
+		return true
+	default:
+		return false
+	}
+}
+
+// IsLeaf returns true if 'n' is a leaf node.
+func (n *Node) IsLeaf() bool {
+	return !n.IsContainer()
+}
+
+func (n *Node) canContain(t NodeType) bool {
+	if n.Type == List {
+		return t == Item
+	}
+	if n.Type == Document || n.Type == BlockQuote || n.Type == Item {
+		return t != Item
+	}
+	if n.Type == Table {
+		return t == TableHead || t == TableBody
+	}
+	if n.Type == TableHead || n.Type == TableBody {
+		return t == TableRow
+	}
+	if n.Type == TableRow {
+		return t == TableCell
+	}
+	return false
+}
+
+// WalkStatus allows NodeVisitor to have some control over the tree traversal.
+// It is returned from NodeVisitor and different values allow Node.Walk to
+// decide which node to go to next.
+type WalkStatus int
+
+const (
+	// GoToNext is the default traversal of every node.
+	GoToNext WalkStatus = iota
+	// SkipChildren tells walker to skip all children of current node.
+	SkipChildren
+	// Terminate tells walker to terminate the traversal.
+	Terminate
+)
+
+// NodeVisitor is a callback to be called when traversing the syntax tree.
+// Called twice for every node: once with entering=true when the branch is
+// first visited, then with entering=false after all the children are done.
+type NodeVisitor func(node *Node, entering bool) WalkStatus
+
+// Walk is a convenience method that instantiates a walker and starts a
+// traversal of subtree rooted at n.
+func (n *Node) Walk(visitor NodeVisitor) {
+	w := newNodeWalker(n)
+	for w.current != nil {
+		status := visitor(w.current, w.entering)
+		switch status {
+		case GoToNext:
+			w.next()
+		case SkipChildren:
+			w.entering = false
+			w.next()
+		case Terminate:
+			return
+		}
+	}
+}
+
+type nodeWalker struct {
+	current  *Node
+	root     *Node
+	entering bool
+}
+
+func newNodeWalker(root *Node) *nodeWalker {
+	return &nodeWalker{
+		current:  root,
+		root:     root,
+		entering: true,
+	}
+}
+
+func (nw *nodeWalker) next() {
+	if (!nw.current.IsContainer() || !nw.entering) && nw.current == nw.root {
+		nw.current = nil
+		return
+	}
+	if nw.entering && nw.current.IsContainer() {
+		if nw.current.FirstChild != nil {
+			nw.current = nw.current.FirstChild
+			nw.entering = true
+		} else {
+			nw.entering = false
+		}
+	} else if nw.current.Next == nil {
+		nw.current = nw.current.Parent
+		nw.entering = false
+	} else {
+		nw.current = nw.current.Next
+		nw.entering = true
+	}
+}
+
+func dump(ast *Node) {
+	fmt.Println(dumpString(ast))
+}
+
+func dumpR(ast *Node, depth int) string {
+	if ast == nil {
+		return ""
+	}
+	indent := bytes.Repeat([]byte("\t"), depth)
+	content := ast.Literal
+	if content == nil {
+		content = ast.content
+	}
+	result := fmt.Sprintf("%s%s(%q)\n", indent, ast.Type, content)
+	for n := ast.FirstChild; n != nil; n = n.Next {
+		result += dumpR(n, depth+1)
+	}
+	return result
+}
+
+func dumpString(ast *Node) string {
+	return dumpR(ast, 0)
+}
diff --git a/vendor/github.com/russross/blackfriday/v2/smartypants.go b/vendor/github.com/russross/blackfriday/v2/smartypants.go
new file mode 100644
index 000000000000..3a220e94247d
--- /dev/null
+++ b/vendor/github.com/russross/blackfriday/v2/smartypants.go
@@ -0,0 +1,457 @@
+//
+// Blackfriday Markdown Processor
+// Available at http://github.com/russross/blackfriday
+//
+// Copyright © 2011 Russ Ross <russ@russross.com>.
+// Distributed under the Simplified BSD License.
+// See README.md for details.
+//
+
+//
+//
+// SmartyPants rendering
+//
+//
+
+package blackfriday
+
+import (
+	"bytes"
+	"io"
+)
+
+// SPRenderer is a struct containing state of a Smartypants renderer.
+type SPRenderer struct {
+	inSingleQuote bool
+	inDoubleQuote bool
+	callbacks     [256]smartCallback
+}
+
+func wordBoundary(c byte) bool {
+	return c == 0 || isspace(c) || ispunct(c)
+}
+
+func tolower(c byte) byte {
+	if c >= 'A' && c <= 'Z' {
+		return c - 'A' + 'a'
+	}
+	return c
+}
+
+func isdigit(c byte) bool {
+	return c >= '0' && c <= '9'
+}
+
+func smartQuoteHelper(out *bytes.Buffer, previousChar byte, nextChar byte, quote byte, isOpen *bool, addNBSP bool) bool {
+	// edge of the buffer is likely to be a tag that we don't get to see,
+	// so we treat it like text sometimes
+
+	// enumerate all sixteen possibilities for (previousChar, nextChar)
+	// each can be one of {0, space, punct, other}
+	switch {
+	case previousChar == 0 && nextChar == 0:
+		// context is not any help here, so toggle
+		*isOpen = !*isOpen
+	case isspace(previousChar) && nextChar == 0:
+		// [ "] might be [ "<code>foo...]
+		*isOpen = true
+	case ispunct(previousChar) && nextChar == 0:
+		// [!"] hmm... could be [Run!"] or [("<code>...]
+		*isOpen = false
+	case /* isnormal(previousChar) && */ nextChar == 0:
+		// [a"] is probably a close
+		*isOpen = false
+	case previousChar == 0 && isspace(nextChar):
+		// [" ] might be [...foo</code>" ]
+		*isOpen = false
+	case isspace(previousChar) && isspace(nextChar):
+		// [ " ] context is not any help here, so toggle
+		*isOpen = !*isOpen
+	case ispunct(previousChar) && isspace(nextChar):
+		// [!" ] is probably a close
+		*isOpen = false
+	case /* isnormal(previousChar) && */ isspace(nextChar):
+		// [a" ] this is one of the easy cases
+		*isOpen = false
+	case previousChar == 0 && ispunct(nextChar):
+		// ["!] hmm... could be ["$1.95] or [</code>"!...]
+		*isOpen = false
+	case isspace(previousChar) && ispunct(nextChar):
+		// [ "!] looks more like [ "$1.95]
+		*isOpen = true
+	case ispunct(previousChar) && ispunct(nextChar):
+		// [!"!] context is not any help here, so toggle
+		*isOpen = !*isOpen
+	case /* isnormal(previousChar) && */ ispunct(nextChar):
+		// [a"!] is probably a close
+		*isOpen = false
+	case previousChar == 0 /* && isnormal(nextChar) */ :
+		// ["a] is probably an open
+		*isOpen = true
+	case isspace(previousChar) /* && isnormal(nextChar) */ :
+		// [ "a] this is one of the easy cases
+		*isOpen = true
+	case ispunct(previousChar) /* && isnormal(nextChar) */ :
+		// [!"a] is probably an open
+		*isOpen = true
+	default:
+		// [a'b] maybe a contraction?
+		*isOpen = false
+	}
+
+	// Note that with the limited lookahead, this non-breaking
+	// space will also be appended to single double quotes.
+	if addNBSP && !*isOpen {
+		out.WriteString("&nbsp;")
+	}
+
+	out.WriteByte('&')
+	if *isOpen {
+		out.WriteByte('l')
+	} else {
+		out.WriteByte('r')
+	}
+	out.WriteByte(quote)
+	out.WriteString("quo;")
+
+	if addNBSP && *isOpen {
+		out.WriteString("&nbsp;")
+	}
+
+	return true
+}
+
+func (r *SPRenderer) smartSingleQuote(out *bytes.Buffer, previousChar byte, text []byte) int {
+	if len(text) >= 2 {
+		t1 := tolower(text[1])
+
+		if t1 == '\'' {
+			nextChar := byte(0)
+			if len(text) >= 3 {
+				nextChar = text[2]
+			}
+			if smartQuoteHelper(out, previousChar, nextChar, 'd', &r.inDoubleQuote, false) {
+				return 1
+			}
+		}
+
+		if (t1 == 's' || t1 == 't' || t1 == 'm' || t1 == 'd') && (len(text) < 3 || wordBoundary(text[2])) {
+			out.WriteString("&rsquo;")
+			return 0
+		}
+
+		if len(text) >= 3 {
+			t2 := tolower(text[2])
+
+			if ((t1 == 'r' && t2 == 'e') || (t1 == 'l' && t2 == 'l') || (t1 == 'v' && t2 == 'e')) &&
+				(len(text) < 4 || wordBoundary(text[3])) {
+				out.WriteString("&rsquo;")
+				return 0
+			}
+		}
+	}
+
+	nextChar := byte(0)
+	if len(text) > 1 {
+		nextChar = text[1]
+	}
+	if smartQuoteHelper(out, previousChar, nextChar, 's', &r.inSingleQuote, false) {
+		return 0
+	}
+
+	out.WriteByte(text[0])
+	return 0
+}
+
+func (r *SPRenderer) smartParens(out *bytes.Buffer, previousChar byte, text []byte) int {
+	if len(text) >= 3 {
+		t1 := tolower(text[1])
+		t2 := tolower(text[2])
+
+		if t1 == 'c' && t2 == ')' {
+			out.WriteString("&copy;")
+			return 2
+		}
+
+		if t1 == 'r' && t2 == ')' {
+			out.WriteString("&reg;")
+			return 2
+		}
+
+		if len(text) >= 4 && t1 == 't' && t2 == 'm' && text[3] == ')' {
+			out.WriteString("&trade;")
+			return 3
+		}
+	}
+
+	out.WriteByte(text[0])
+	return 0
+}
+
+func (r *SPRenderer) smartDash(out *bytes.Buffer, previousChar byte, text []byte) int {
+	if len(text) >= 2 {
+		if text[1] == '-' {
+			out.WriteString("&mdash;")
+			return 1
+		}
+
+		if wordBoundary(previousChar) && wordBoundary(text[1]) {
+			out.WriteString("&ndash;")
+			return 0
+		}
+	}
+
+	out.WriteByte(text[0])
+	return 0
+}
+
+func (r *SPRenderer) smartDashLatex(out *bytes.Buffer, previousChar byte, text []byte) int {
+	if len(text) >= 3 && text[1] == '-' && text[2] == '-' {
+		out.WriteString("&mdash;")
+		return 2
+	}
+	if len(text) >= 2 && text[1] == '-' {
+		out.WriteString("&ndash;")
+		return 1
+	}
+
+	out.WriteByte(text[0])
+	return 0
+}
+
+func (r *SPRenderer) smartAmpVariant(out *bytes.Buffer, previousChar byte, text []byte, quote byte, addNBSP bool) int {
+	if bytes.HasPrefix(text, []byte("&quot;")) {
+		nextChar := byte(0)
+		if len(text) >= 7 {
+			nextChar = text[6]
+		}
+		if smartQuoteHelper(out, previousChar, nextChar, quote, &r.inDoubleQuote, addNBSP) {
+			return 5
+		}
+	}
+
+	if bytes.HasPrefix(text, []byte("&#0;")) {
+		return 3
+	}
+
+	out.WriteByte('&')
+	return 0
+}
+
+func (r *SPRenderer) smartAmp(angledQuotes, addNBSP bool) func(*bytes.Buffer, byte, []byte) int {
+	var quote byte = 'd'
+	if angledQuotes {
+		quote = 'a'
+	}
+
+	return func(out *bytes.Buffer, previousChar byte, text []byte) int {
+		return r.smartAmpVariant(out, previousChar, text, quote, addNBSP)
+	}
+}
+
+func (r *SPRenderer) smartPeriod(out *bytes.Buffer, previousChar byte, text []byte) int {
+	if len(text) >= 3 && text[1] == '.' && text[2] == '.' {
+		out.WriteString("&hellip;")
+		return 2
+	}
+
+	if len(text) >= 5 && text[1] == ' ' && text[2] == '.' && text[3] == ' ' && text[4] == '.' {
+		out.WriteString("&hellip;")
+		return 4
+	}
+
+	out.WriteByte(text[0])
+	return 0
+}
+
+func (r *SPRenderer) smartBacktick(out *bytes.Buffer, previousChar byte, text []byte) int {
+	if len(text) >= 2 && text[1] == '`' {
+		nextChar := byte(0)
+		if len(text) >= 3 {
+			nextChar = text[2]
+		}
+		if smartQuoteHelper(out, previousChar, nextChar, 'd', &r.inDoubleQuote, false) {
+			return 1
+		}
+	}
+
+	out.WriteByte(text[0])
+	return 0
+}
+
+func (r *SPRenderer) smartNumberGeneric(out *bytes.Buffer, previousChar byte, text []byte) int {
+	if wordBoundary(previousChar) && previousChar != '/' && len(text) >= 3 {
+		// is it of the form digits/digits(word boundary)?, i.e., \d+/\d+\b
+		// note: check for regular slash (/) or fraction slash (⁄, 0x2044, or 0xe2 81 84 in utf-8)
+		//       and avoid changing dates like 1/23/2005 into fractions.
+		numEnd := 0
+		for len(text) > numEnd && isdigit(text[numEnd]) {
+			numEnd++
+		}
+		if numEnd == 0 {
+			out.WriteByte(text[0])
+			return 0
+		}
+		denStart := numEnd + 1
+		if len(text) > numEnd+3 && text[numEnd] == 0xe2 && text[numEnd+1] == 0x81 && text[numEnd+2] == 0x84 {
+			denStart = numEnd + 3
+		} else if len(text) < numEnd+2 || text[numEnd] != '/' {
+			out.WriteByte(text[0])
+			return 0
+		}
+		denEnd := denStart
+		for len(text) > denEnd && isdigit(text[denEnd]) {
+			denEnd++
+		}
+		if denEnd == denStart {
+			out.WriteByte(text[0])
+			return 0
+		}
+		if len(text) == denEnd || wordBoundary(text[denEnd]) && text[denEnd] != '/' {
+			out.WriteString("<sup>")
+			out.Write(text[:numEnd])
+			out.WriteString("</sup>&frasl;<sub>")
+			out.Write(text[denStart:denEnd])
+			out.WriteString("</sub>")
+			return denEnd - 1
+		}
+	}
+
+	out.WriteByte(text[0])
+	return 0
+}
+
+func (r *SPRenderer) smartNumber(out *bytes.Buffer, previousChar byte, text []byte) int {
+	if wordBoundary(previousChar) && previousChar != '/' && len(text) >= 3 {
+		if text[0] == '1' && text[1] == '/' && text[2] == '2' {
+			if len(text) < 4 || wordBoundary(text[3]) && text[3] != '/' {
+				out.WriteString("&frac12;")
+				return 2
+			}
+		}
+
+		if text[0] == '1' && text[1] == '/' && text[2] == '4' {
+			if len(text) < 4 || wordBoundary(text[3]) && text[3] != '/' || (len(text) >= 5 && tolower(text[3]) == 't' && tolower(text[4]) == 'h') {
+				out.WriteString("&frac14;")
+				return 2
+			}
+		}
+
+		if text[0] == '3' && text[1] == '/' && text[2] == '4' {
+			if len(text) < 4 || wordBoundary(text[3]) && text[3] != '/' || (len(text) >= 6 && tolower(text[3]) == 't' && tolower(text[4]) == 'h' && tolower(text[5]) == 's') {
+				out.WriteString("&frac34;")
+				return 2
+			}
+		}
+	}
+
+	out.WriteByte(text[0])
+	return 0
+}
+
+func (r *SPRenderer) smartDoubleQuoteVariant(out *bytes.Buffer, previousChar byte, text []byte, quote byte) int {
+	nextChar := byte(0)
+	if len(text) > 1 {
+		nextChar = text[1]
+	}
+	if !smartQuoteHelper(out, previousChar, nextChar, quote, &r.inDoubleQuote, false) {
+		out.WriteString("&quot;")
+	}
+
+	return 0
+}
+
+func (r *SPRenderer) smartDoubleQuote(out *bytes.Buffer, previousChar byte, text []byte) int {
+	return r.smartDoubleQuoteVariant(out, previousChar, text, 'd')
+}
+
+func (r *SPRenderer) smartAngledDoubleQuote(out *bytes.Buffer, previousChar byte, text []byte) int {
+	return r.smartDoubleQuoteVariant(out, previousChar, text, 'a')
+}
+
+func (r *SPRenderer) smartLeftAngle(out *bytes.Buffer, previousChar byte, text []byte) int {
+	i := 0
+
+	for i < len(text) && text[i] != '>' {
+		i++
+	}
+
+	out.Write(text[:i+1])
+	return i
+}
+
+type smartCallback func(out *bytes.Buffer, previousChar byte, text []byte) int
+
+// NewSmartypantsRenderer constructs a Smartypants renderer object.
+func NewSmartypantsRenderer(flags HTMLFlags) *SPRenderer {
+	var (
+		r SPRenderer
+
+		smartAmpAngled      = r.smartAmp(true, false)
+		smartAmpAngledNBSP  = r.smartAmp(true, true)
+		smartAmpRegular     = r.smartAmp(false, false)
+		smartAmpRegularNBSP = r.smartAmp(false, true)
+
+		addNBSP = flags&SmartypantsQuotesNBSP != 0
+	)
+
+	if flags&SmartypantsAngledQuotes == 0 {
+		r.callbacks['"'] = r.smartDoubleQuote
+		if !addNBSP {
+			r.callbacks['&'] = smartAmpRegular
+		} else {
+			r.callbacks['&'] = smartAmpRegularNBSP
+		}
+	} else {
+		r.callbacks['"'] = r.smartAngledDoubleQuote
+		if !addNBSP {
+			r.callbacks['&'] = smartAmpAngled
+		} else {
+			r.callbacks['&'] = smartAmpAngledNBSP
+		}
+	}
+	r.callbacks['\''] = r.smartSingleQuote
+	r.callbacks['('] = r.smartParens
+	if flags&SmartypantsDashes != 0 {
+		if flags&SmartypantsLatexDashes == 0 {
+			r.callbacks['-'] = r.smartDash
+		} else {
+			r.callbacks['-'] = r.smartDashLatex
+		}
+	}
+	r.callbacks['.'] = r.smartPeriod
+	if flags&SmartypantsFractions == 0 {
+		r.callbacks['1'] = r.smartNumber
+		r.callbacks['3'] = r.smartNumber
+	} else {
+		for ch := '1'; ch <= '9'; ch++ {
+			r.callbacks[ch] = r.smartNumberGeneric
+		}
+	}
+	r.callbacks['<'] = r.smartLeftAngle
+	r.callbacks['`'] = r.smartBacktick
+	return &r
+}
+
+// Process is the entry point of the Smartypants renderer.
+func (r *SPRenderer) Process(w io.Writer, text []byte) {
+	mark := 0
+	for i := 0; i < len(text); i++ {
+		if action := r.callbacks[text[i]]; action != nil {
+			if i > mark {
+				w.Write(text[mark:i])
+			}
+			previousChar := byte(0)
+			if i > 0 {
+				previousChar = text[i-1]
+			}
+			var tmp bytes.Buffer
+			i += action(&tmp, previousChar, text[i:])
+			w.Write(tmp.Bytes())
+			mark = i + 1
+		}
+	}
+	if mark < len(text) {
+		w.Write(text[mark:])
+	}
+}
diff --git a/vendor/github.com/spf13/cobra/doc/man_docs.go b/vendor/github.com/spf13/cobra/doc/man_docs.go
new file mode 100644
index 000000000000..b8c15ce88543
--- /dev/null
+++ b/vendor/github.com/spf13/cobra/doc/man_docs.go
@@ -0,0 +1,246 @@
+// Copyright 2013-2023 The Cobra Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package doc
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"sort"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/cpuguy83/go-md2man/v2/md2man"
+	"github.com/spf13/cobra"
+	"github.com/spf13/pflag"
+)
+
+// GenManTree will generate a man page for this command and all descendants
+// in the directory given. The header may be nil. This function may not work
+// correctly if your command names have `-` in them. If you have `cmd` with two
+// subcmds, `sub` and `sub-third`, and `sub` has a subcommand called `third`
+// it is undefined which help output will be in the file `cmd-sub-third.1`.
+func GenManTree(cmd *cobra.Command, header *GenManHeader, dir string) error {
+	return GenManTreeFromOpts(cmd, GenManTreeOptions{
+		Header:           header,
+		Path:             dir,
+		CommandSeparator: "-",
+	})
+}
+
+// GenManTreeFromOpts generates a man page for the command and all descendants.
+// The pages are written to the opts.Path directory.
+func GenManTreeFromOpts(cmd *cobra.Command, opts GenManTreeOptions) error {
+	header := opts.Header
+	if header == nil {
+		header = &GenManHeader{}
+	}
+	for _, c := range cmd.Commands() {
+		if !c.IsAvailableCommand() || c.IsAdditionalHelpTopicCommand() {
+			continue
+		}
+		if err := GenManTreeFromOpts(c, opts); err != nil {
+			return err
+		}
+	}
+	section := "1"
+	if header.Section != "" {
+		section = header.Section
+	}
+
+	separator := "_"
+	if opts.CommandSeparator != "" {
+		separator = opts.CommandSeparator
+	}
+	basename := strings.ReplaceAll(cmd.CommandPath(), " ", separator)
+	filename := filepath.Join(opts.Path, basename+"."+section)
+	f, err := os.Create(filename)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+
+	headerCopy := *header
+	return GenMan(cmd, &headerCopy, f)
+}
+
+// GenManTreeOptions is the options for generating the man pages.
+// Used only in GenManTreeFromOpts.
+type GenManTreeOptions struct {
+	Header           *GenManHeader
+	Path             string
+	CommandSeparator string
+}
+
+// GenManHeader is a lot like the .TH header at the start of man pages. These
+// include the title, section, date, source, and manual. We will use the
+// current time if Date is unset and will use "Auto generated by spf13/cobra"
+// if the Source is unset.
+type GenManHeader struct {
+	Title   string
+	Section string
+	Date    *time.Time
+	date    string
+	Source  string
+	Manual  string
+}
+
+// GenMan will generate a man page for the given command and write it to
+// w. The header argument may be nil, however obviously w may not.
+func GenMan(cmd *cobra.Command, header *GenManHeader, w io.Writer) error {
+	if header == nil {
+		header = &GenManHeader{}
+	}
+	if err := fillHeader(header, cmd.CommandPath(), cmd.DisableAutoGenTag); err != nil {
+		return err
+	}
+
+	b := genMan(cmd, header)
+	_, err := w.Write(md2man.Render(b))
+	return err
+}
+
+func fillHeader(header *GenManHeader, name string, disableAutoGen bool) error {
+	if header.Title == "" {
+		header.Title = strings.ToUpper(strings.ReplaceAll(name, " ", "\\-"))
+	}
+	if header.Section == "" {
+		header.Section = "1"
+	}
+	if header.Date == nil {
+		now := time.Now()
+		if epoch := os.Getenv("SOURCE_DATE_EPOCH"); epoch != "" {
+			unixEpoch, err := strconv.ParseInt(epoch, 10, 64)
+			if err != nil {
+				return fmt.Errorf("invalid SOURCE_DATE_EPOCH: %v", err)
+			}
+			now = time.Unix(unixEpoch, 0)
+		}
+		header.Date = &now
+	}
+	header.date = (*header.Date).Format("Jan 2006")
+	if header.Source == "" && !disableAutoGen {
+		header.Source = "Auto generated by spf13/cobra"
+	}
+	return nil
+}
+
+func manPreamble(buf io.StringWriter, header *GenManHeader, cmd *cobra.Command, dashedName string) {
+	description := cmd.Long
+	if len(description) == 0 {
+		description = cmd.Short
+	}
+
+	cobra.WriteStringAndCheck(buf, fmt.Sprintf(`%% "%s" "%s" "%s" "%s" "%s"
+# NAME
+`, header.Title, header.Section, header.date, header.Source, header.Manual))
+	cobra.WriteStringAndCheck(buf, fmt.Sprintf("%s \\- %s\n\n", dashedName, cmd.Short))
+	cobra.WriteStringAndCheck(buf, "# SYNOPSIS\n")
+	cobra.WriteStringAndCheck(buf, fmt.Sprintf("**%s**\n\n", cmd.UseLine()))
+	cobra.WriteStringAndCheck(buf, "# DESCRIPTION\n")
+	cobra.WriteStringAndCheck(buf, description+"\n\n")
+}
+
+func manPrintFlags(buf io.StringWriter, flags *pflag.FlagSet) {
+	flags.VisitAll(func(flag *pflag.Flag) {
+		if len(flag.Deprecated) > 0 || flag.Hidden {
+			return
+		}
+		format := ""
+		if len(flag.Shorthand) > 0 && len(flag.ShorthandDeprecated) == 0 {
+			format = fmt.Sprintf("**-%s**, **--%s**", flag.Shorthand, flag.Name)
+		} else {
+			format = fmt.Sprintf("**--%s**", flag.Name)
+		}
+		if len(flag.NoOptDefVal) > 0 {
+			format += "["
+		}
+		if flag.Value.Type() == "string" {
+			// put quotes on the value
+			format += "=%q"
+		} else {
+			format += "=%s"
+		}
+		if len(flag.NoOptDefVal) > 0 {
+			format += "]"
+		}
+		format += "\n\t%s\n\n"
+		cobra.WriteStringAndCheck(buf, fmt.Sprintf(format, flag.DefValue, flag.Usage))
+	})
+}
+
+func manPrintOptions(buf io.StringWriter, command *cobra.Command) {
+	flags := command.NonInheritedFlags()
+	if flags.HasAvailableFlags() {
+		cobra.WriteStringAndCheck(buf, "# OPTIONS\n")
+		manPrintFlags(buf, flags)
+		cobra.WriteStringAndCheck(buf, "\n")
+	}
+	flags = command.InheritedFlags()
+	if flags.HasAvailableFlags() {
+		cobra.WriteStringAndCheck(buf, "# OPTIONS INHERITED FROM PARENT COMMANDS\n")
+		manPrintFlags(buf, flags)
+		cobra.WriteStringAndCheck(buf, "\n")
+	}
+}
+
+func genMan(cmd *cobra.Command, header *GenManHeader) []byte {
+	cmd.InitDefaultHelpCmd()
+	cmd.InitDefaultHelpFlag()
+
+	// something like `rootcmd-subcmd1-subcmd2`
+	dashCommandName := strings.ReplaceAll(cmd.CommandPath(), " ", "-")
+
+	buf := new(bytes.Buffer)
+
+	manPreamble(buf, header, cmd, dashCommandName)
+	manPrintOptions(buf, cmd)
+	if len(cmd.Example) > 0 {
+		buf.WriteString("# EXAMPLE\n")
+		buf.WriteString(fmt.Sprintf("```\n%s\n```\n", cmd.Example))
+	}
+	if hasSeeAlso(cmd) {
+		buf.WriteString("# SEE ALSO\n")
+		seealsos := make([]string, 0)
+		if cmd.HasParent() {
+			parentPath := cmd.Parent().CommandPath()
+			dashParentPath := strings.ReplaceAll(parentPath, " ", "-")
+			seealso := fmt.Sprintf("**%s(%s)**", dashParentPath, header.Section)
+			seealsos = append(seealsos, seealso)
+			cmd.VisitParents(func(c *cobra.Command) {
+				if c.DisableAutoGenTag {
+					cmd.DisableAutoGenTag = c.DisableAutoGenTag
+				}
+			})
+		}
+		children := cmd.Commands()
+		sort.Sort(byName(children))
+		for _, c := range children {
+			if !c.IsAvailableCommand() || c.IsAdditionalHelpTopicCommand() {
+				continue
+			}
+			seealso := fmt.Sprintf("**%s-%s(%s)**", dashCommandName, c.Name(), header.Section)
+			seealsos = append(seealsos, seealso)
+		}
+		buf.WriteString(strings.Join(seealsos, ", ") + "\n")
+	}
+	if !cmd.DisableAutoGenTag {
+		buf.WriteString(fmt.Sprintf("# HISTORY\n%s Auto generated by spf13/cobra\n", header.Date.Format("2-Jan-2006")))
+	}
+	return buf.Bytes()
+}
diff --git a/vendor/github.com/spf13/cobra/doc/md_docs.go b/vendor/github.com/spf13/cobra/doc/md_docs.go
new file mode 100644
index 000000000000..f98fe2a3b8f3
--- /dev/null
+++ b/vendor/github.com/spf13/cobra/doc/md_docs.go
@@ -0,0 +1,158 @@
+// Copyright 2013-2023 The Cobra Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package doc
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"sort"
+	"strings"
+	"time"
+
+	"github.com/spf13/cobra"
+)
+
+const markdownExtension = ".md"
+
+func printOptions(buf *bytes.Buffer, cmd *cobra.Command, name string) error {
+	flags := cmd.NonInheritedFlags()
+	flags.SetOutput(buf)
+	if flags.HasAvailableFlags() {
+		buf.WriteString("### Options\n\n```\n")
+		flags.PrintDefaults()
+		buf.WriteString("```\n\n")
+	}
+
+	parentFlags := cmd.InheritedFlags()
+	parentFlags.SetOutput(buf)
+	if parentFlags.HasAvailableFlags() {
+		buf.WriteString("### Options inherited from parent commands\n\n```\n")
+		parentFlags.PrintDefaults()
+		buf.WriteString("```\n\n")
+	}
+	return nil
+}
+
+// GenMarkdown creates markdown output.
+func GenMarkdown(cmd *cobra.Command, w io.Writer) error {
+	return GenMarkdownCustom(cmd, w, func(s string) string { return s })
+}
+
+// GenMarkdownCustom creates custom markdown output.
+func GenMarkdownCustom(cmd *cobra.Command, w io.Writer, linkHandler func(string) string) error {
+	cmd.InitDefaultHelpCmd()
+	cmd.InitDefaultHelpFlag()
+
+	buf := new(bytes.Buffer)
+	name := cmd.CommandPath()
+
+	buf.WriteString("## " + name + "\n\n")
+	buf.WriteString(cmd.Short + "\n\n")
+	if len(cmd.Long) > 0 {
+		buf.WriteString("### Synopsis\n\n")
+		buf.WriteString(cmd.Long + "\n\n")
+	}
+
+	if cmd.Runnable() {
+		buf.WriteString(fmt.Sprintf("```\n%s\n```\n\n", cmd.UseLine()))
+	}
+
+	if len(cmd.Example) > 0 {
+		buf.WriteString("### Examples\n\n")
+		buf.WriteString(fmt.Sprintf("```\n%s\n```\n\n", cmd.Example))
+	}
+
+	if err := printOptions(buf, cmd, name); err != nil {
+		return err
+	}
+	if hasSeeAlso(cmd) {
+		buf.WriteString("### SEE ALSO\n\n")
+		if cmd.HasParent() {
+			parent := cmd.Parent()
+			pname := parent.CommandPath()
+			link := pname + markdownExtension
+			link = strings.ReplaceAll(link, " ", "_")
+			buf.WriteString(fmt.Sprintf("* [%s](%s)\t - %s\n", pname, linkHandler(link), parent.Short))
+			cmd.VisitParents(func(c *cobra.Command) {
+				if c.DisableAutoGenTag {
+					cmd.DisableAutoGenTag = c.DisableAutoGenTag
+				}
+			})
+		}
+
+		children := cmd.Commands()
+		sort.Sort(byName(children))
+
+		for _, child := range children {
+			if !child.IsAvailableCommand() || child.IsAdditionalHelpTopicCommand() {
+				continue
+			}
+			cname := name + " " + child.Name()
+			link := cname + markdownExtension
+			link = strings.ReplaceAll(link, " ", "_")
+			buf.WriteString(fmt.Sprintf("* [%s](%s)\t - %s\n", cname, linkHandler(link), child.Short))
+		}
+		buf.WriteString("\n")
+	}
+	if !cmd.DisableAutoGenTag {
+		buf.WriteString("###### Auto generated by spf13/cobra on " + time.Now().Format("2-Jan-2006") + "\n")
+	}
+	_, err := buf.WriteTo(w)
+	return err
+}
+
+// GenMarkdownTree will generate a markdown page for this command and all
+// descendants in the directory given. The header may be nil.
+// This function may not work correctly if your command names have `-` in them.
+// If you have `cmd` with two subcmds, `sub` and `sub-third`,
+// and `sub` has a subcommand called `third`, it is undefined which
+// help output will be in the file `cmd-sub-third.1`.
+func GenMarkdownTree(cmd *cobra.Command, dir string) error {
+	identity := func(s string) string { return s }
+	emptyStr := func(s string) string { return "" }
+	return GenMarkdownTreeCustom(cmd, dir, emptyStr, identity)
+}
+
+// GenMarkdownTreeCustom is the the same as GenMarkdownTree, but
+// with custom filePrepender and linkHandler.
+func GenMarkdownTreeCustom(cmd *cobra.Command, dir string, filePrepender, linkHandler func(string) string) error {
+	for _, c := range cmd.Commands() {
+		if !c.IsAvailableCommand() || c.IsAdditionalHelpTopicCommand() {
+			continue
+		}
+		if err := GenMarkdownTreeCustom(c, dir, filePrepender, linkHandler); err != nil {
+			return err
+		}
+	}
+
+	basename := strings.ReplaceAll(cmd.CommandPath(), " ", "_") + markdownExtension
+	filename := filepath.Join(dir, basename)
+	f, err := os.Create(filename)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+
+	if _, err := io.WriteString(f, filePrepender(filename)); err != nil {
+		return err
+	}
+	if err := GenMarkdownCustom(cmd, f, linkHandler); err != nil {
+		return err
+	}
+	return nil
+}
diff --git a/vendor/github.com/spf13/cobra/doc/rest_docs.go b/vendor/github.com/spf13/cobra/doc/rest_docs.go
new file mode 100644
index 000000000000..2cca6fd778de
--- /dev/null
+++ b/vendor/github.com/spf13/cobra/doc/rest_docs.go
@@ -0,0 +1,186 @@
+// Copyright 2013-2023 The Cobra Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package doc
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"sort"
+	"strings"
+	"time"
+
+	"github.com/spf13/cobra"
+)
+
+func printOptionsReST(buf *bytes.Buffer, cmd *cobra.Command, name string) error {
+	flags := cmd.NonInheritedFlags()
+	flags.SetOutput(buf)
+	if flags.HasAvailableFlags() {
+		buf.WriteString("Options\n")
+		buf.WriteString("~~~~~~~\n\n::\n\n")
+		flags.PrintDefaults()
+		buf.WriteString("\n")
+	}
+
+	parentFlags := cmd.InheritedFlags()
+	parentFlags.SetOutput(buf)
+	if parentFlags.HasAvailableFlags() {
+		buf.WriteString("Options inherited from parent commands\n")
+		buf.WriteString("~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n\n::\n\n")
+		parentFlags.PrintDefaults()
+		buf.WriteString("\n")
+	}
+	return nil
+}
+
+// defaultLinkHandler for default ReST hyperlink markup
+func defaultLinkHandler(name, ref string) string {
+	return fmt.Sprintf("`%s <%s.rst>`_", name, ref)
+}
+
+// GenReST creates reStructured Text output.
+func GenReST(cmd *cobra.Command, w io.Writer) error {
+	return GenReSTCustom(cmd, w, defaultLinkHandler)
+}
+
+// GenReSTCustom creates custom reStructured Text output.
+func GenReSTCustom(cmd *cobra.Command, w io.Writer, linkHandler func(string, string) string) error {
+	cmd.InitDefaultHelpCmd()
+	cmd.InitDefaultHelpFlag()
+
+	buf := new(bytes.Buffer)
+	name := cmd.CommandPath()
+
+	short := cmd.Short
+	long := cmd.Long
+	if len(long) == 0 {
+		long = short
+	}
+	ref := strings.ReplaceAll(name, " ", "_")
+
+	buf.WriteString(".. _" + ref + ":\n\n")
+	buf.WriteString(name + "\n")
+	buf.WriteString(strings.Repeat("-", len(name)) + "\n\n")
+	buf.WriteString(short + "\n\n")
+	buf.WriteString("Synopsis\n")
+	buf.WriteString("~~~~~~~~\n\n")
+	buf.WriteString("\n" + long + "\n\n")
+
+	if cmd.Runnable() {
+		buf.WriteString(fmt.Sprintf("::\n\n  %s\n\n", cmd.UseLine()))
+	}
+
+	if len(cmd.Example) > 0 {
+		buf.WriteString("Examples\n")
+		buf.WriteString("~~~~~~~~\n\n")
+		buf.WriteString(fmt.Sprintf("::\n\n%s\n\n", indentString(cmd.Example, "  ")))
+	}
+
+	if err := printOptionsReST(buf, cmd, name); err != nil {
+		return err
+	}
+	if hasSeeAlso(cmd) {
+		buf.WriteString("SEE ALSO\n")
+		buf.WriteString("~~~~~~~~\n\n")
+		if cmd.HasParent() {
+			parent := cmd.Parent()
+			pname := parent.CommandPath()
+			ref = strings.ReplaceAll(pname, " ", "_")
+			buf.WriteString(fmt.Sprintf("* %s \t - %s\n", linkHandler(pname, ref), parent.Short))
+			cmd.VisitParents(func(c *cobra.Command) {
+				if c.DisableAutoGenTag {
+					cmd.DisableAutoGenTag = c.DisableAutoGenTag
+				}
+			})
+		}
+
+		children := cmd.Commands()
+		sort.Sort(byName(children))
+
+		for _, child := range children {
+			if !child.IsAvailableCommand() || child.IsAdditionalHelpTopicCommand() {
+				continue
+			}
+			cname := name + " " + child.Name()
+			ref = strings.ReplaceAll(cname, " ", "_")
+			buf.WriteString(fmt.Sprintf("* %s \t - %s\n", linkHandler(cname, ref), child.Short))
+		}
+		buf.WriteString("\n")
+	}
+	if !cmd.DisableAutoGenTag {
+		buf.WriteString("*Auto generated by spf13/cobra on " + time.Now().Format("2-Jan-2006") + "*\n")
+	}
+	_, err := buf.WriteTo(w)
+	return err
+}
+
+// GenReSTTree will generate a ReST page for this command and all
+// descendants in the directory given.
+// This function may not work correctly if your command names have `-` in them.
+// If you have `cmd` with two subcmds, `sub` and `sub-third`,
+// and `sub` has a subcommand called `third`, it is undefined which
+// help output will be in the file `cmd-sub-third.1`.
+func GenReSTTree(cmd *cobra.Command, dir string) error {
+	emptyStr := func(s string) string { return "" }
+	return GenReSTTreeCustom(cmd, dir, emptyStr, defaultLinkHandler)
+}
+
+// GenReSTTreeCustom is the the same as GenReSTTree, but
+// with custom filePrepender and linkHandler.
+func GenReSTTreeCustom(cmd *cobra.Command, dir string, filePrepender func(string) string, linkHandler func(string, string) string) error {
+	for _, c := range cmd.Commands() {
+		if !c.IsAvailableCommand() || c.IsAdditionalHelpTopicCommand() {
+			continue
+		}
+		if err := GenReSTTreeCustom(c, dir, filePrepender, linkHandler); err != nil {
+			return err
+		}
+	}
+
+	basename := strings.ReplaceAll(cmd.CommandPath(), " ", "_") + ".rst"
+	filename := filepath.Join(dir, basename)
+	f, err := os.Create(filename)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+
+	if _, err := io.WriteString(f, filePrepender(filename)); err != nil {
+		return err
+	}
+	if err := GenReSTCustom(cmd, f, linkHandler); err != nil {
+		return err
+	}
+	return nil
+}
+
+// indentString adapted from: https://github.com/kr/text/blob/main/indent.go
+func indentString(s, p string) string {
+	var res []byte
+	b := []byte(s)
+	prefix := []byte(p)
+	bol := true
+	for _, c := range b {
+		if bol && c != '\n' {
+			res = append(res, prefix...)
+		}
+		res = append(res, c)
+		bol = c == '\n'
+	}
+	return string(res)
+}
diff --git a/vendor/github.com/spf13/cobra/doc/util.go b/vendor/github.com/spf13/cobra/doc/util.go
new file mode 100644
index 000000000000..0aaa07a166d8
--- /dev/null
+++ b/vendor/github.com/spf13/cobra/doc/util.go
@@ -0,0 +1,52 @@
+// Copyright 2013-2023 The Cobra Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package doc
+
+import (
+	"strings"
+
+	"github.com/spf13/cobra"
+)
+
+// Test to see if we have a reason to print See Also information in docs
+// Basically this is a test for a parent command or a subcommand which is
+// both not deprecated and not the autogenerated help command.
+func hasSeeAlso(cmd *cobra.Command) bool {
+	if cmd.HasParent() {
+		return true
+	}
+	for _, c := range cmd.Commands() {
+		if !c.IsAvailableCommand() || c.IsAdditionalHelpTopicCommand() {
+			continue
+		}
+		return true
+	}
+	return false
+}
+
+// Temporary workaround for yaml lib generating incorrect yaml with long strings
+// that do not contain \n.
+func forceMultiLine(s string) string {
+	if len(s) > 60 && !strings.Contains(s, "\n") {
+		s = s + "\n"
+	}
+	return s
+}
+
+type byName []*cobra.Command
+
+func (s byName) Len() int           { return len(s) }
+func (s byName) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }
+func (s byName) Less(i, j int) bool { return s[i].Name() < s[j].Name() }
diff --git a/vendor/github.com/spf13/cobra/doc/yaml_docs.go b/vendor/github.com/spf13/cobra/doc/yaml_docs.go
new file mode 100644
index 000000000000..2b26d6ec0f3e
--- /dev/null
+++ b/vendor/github.com/spf13/cobra/doc/yaml_docs.go
@@ -0,0 +1,175 @@
+// Copyright 2013-2023 The Cobra Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package doc
+
+import (
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"sort"
+	"strings"
+
+	"github.com/spf13/cobra"
+	"github.com/spf13/pflag"
+	"gopkg.in/yaml.v3"
+)
+
+type cmdOption struct {
+	Name         string
+	Shorthand    string `yaml:",omitempty"`
+	DefaultValue string `yaml:"default_value,omitempty"`
+	Usage        string `yaml:",omitempty"`
+}
+
+type cmdDoc struct {
+	Name             string
+	Synopsis         string      `yaml:",omitempty"`
+	Description      string      `yaml:",omitempty"`
+	Usage            string      `yaml:",omitempty"`
+	Options          []cmdOption `yaml:",omitempty"`
+	InheritedOptions []cmdOption `yaml:"inherited_options,omitempty"`
+	Example          string      `yaml:",omitempty"`
+	SeeAlso          []string    `yaml:"see_also,omitempty"`
+}
+
+// GenYamlTree creates yaml structured ref files for this command and all descendants
+// in the directory given. This function may not work
+// correctly if your command names have `-` in them. If you have `cmd` with two
+// subcmds, `sub` and `sub-third`, and `sub` has a subcommand called `third`
+// it is undefined which help output will be in the file `cmd-sub-third.1`.
+func GenYamlTree(cmd *cobra.Command, dir string) error {
+	identity := func(s string) string { return s }
+	emptyStr := func(s string) string { return "" }
+	return GenYamlTreeCustom(cmd, dir, emptyStr, identity)
+}
+
+// GenYamlTreeCustom creates yaml structured ref files.
+func GenYamlTreeCustom(cmd *cobra.Command, dir string, filePrepender, linkHandler func(string) string) error {
+	for _, c := range cmd.Commands() {
+		if !c.IsAvailableCommand() || c.IsAdditionalHelpTopicCommand() {
+			continue
+		}
+		if err := GenYamlTreeCustom(c, dir, filePrepender, linkHandler); err != nil {
+			return err
+		}
+	}
+
+	basename := strings.ReplaceAll(cmd.CommandPath(), " ", "_") + ".yaml"
+	filename := filepath.Join(dir, basename)
+	f, err := os.Create(filename)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+
+	if _, err := io.WriteString(f, filePrepender(filename)); err != nil {
+		return err
+	}
+	if err := GenYamlCustom(cmd, f, linkHandler); err != nil {
+		return err
+	}
+	return nil
+}
+
+// GenYaml creates yaml output.
+func GenYaml(cmd *cobra.Command, w io.Writer) error {
+	return GenYamlCustom(cmd, w, func(s string) string { return s })
+}
+
+// GenYamlCustom creates custom yaml output.
+func GenYamlCustom(cmd *cobra.Command, w io.Writer, linkHandler func(string) string) error {
+	cmd.InitDefaultHelpCmd()
+	cmd.InitDefaultHelpFlag()
+
+	yamlDoc := cmdDoc{}
+	yamlDoc.Name = cmd.CommandPath()
+
+	yamlDoc.Synopsis = forceMultiLine(cmd.Short)
+	yamlDoc.Description = forceMultiLine(cmd.Long)
+
+	if cmd.Runnable() {
+		yamlDoc.Usage = cmd.UseLine()
+	}
+
+	if len(cmd.Example) > 0 {
+		yamlDoc.Example = cmd.Example
+	}
+
+	flags := cmd.NonInheritedFlags()
+	if flags.HasFlags() {
+		yamlDoc.Options = genFlagResult(flags)
+	}
+	flags = cmd.InheritedFlags()
+	if flags.HasFlags() {
+		yamlDoc.InheritedOptions = genFlagResult(flags)
+	}
+
+	if hasSeeAlso(cmd) {
+		result := []string{}
+		if cmd.HasParent() {
+			parent := cmd.Parent()
+			result = append(result, parent.CommandPath()+" - "+parent.Short)
+		}
+		children := cmd.Commands()
+		sort.Sort(byName(children))
+		for _, child := range children {
+			if !child.IsAvailableCommand() || child.IsAdditionalHelpTopicCommand() {
+				continue
+			}
+			result = append(result, child.CommandPath()+" - "+child.Short)
+		}
+		yamlDoc.SeeAlso = result
+	}
+
+	final, err := yaml.Marshal(&yamlDoc)
+	if err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
+
+	if _, err := w.Write(final); err != nil {
+		return err
+	}
+	return nil
+}
+
+func genFlagResult(flags *pflag.FlagSet) []cmdOption {
+	var result []cmdOption
+
+	flags.VisitAll(func(flag *pflag.Flag) {
+		// Todo, when we mark a shorthand is deprecated, but specify an empty message.
+		// The flag.ShorthandDeprecated is empty as the shorthand is deprecated.
+		// Using len(flag.ShorthandDeprecated) > 0 can't handle this, others are ok.
+		if !(len(flag.ShorthandDeprecated) > 0) && len(flag.Shorthand) > 0 {
+			opt := cmdOption{
+				flag.Name,
+				flag.Shorthand,
+				flag.DefValue,
+				forceMultiLine(flag.Usage),
+			}
+			result = append(result, opt)
+		} else {
+			opt := cmdOption{
+				Name:         flag.Name,
+				DefaultValue: forceMultiLine(flag.DefValue),
+				Usage:        forceMultiLine(flag.Usage),
+			}
+			result = append(result, opt)
+		}
+	})
+
+	return result
+}
diff --git a/vendor/gopkg.in/yaml.v3/LICENSE b/vendor/gopkg.in/yaml.v3/LICENSE
new file mode 100644
index 000000000000..2683e4bb1f24
--- /dev/null
+++ b/vendor/gopkg.in/yaml.v3/LICENSE
@@ -0,0 +1,50 @@
+
+This project is covered by two different licenses: MIT and Apache.
+
+#### MIT License ####
+
+The following files were ported to Go from C files of libyaml, and thus
+are still covered by their original MIT license, with the additional
+copyright staring in 2011 when the project was ported over:
+
+    apic.go emitterc.go parserc.go readerc.go scannerc.go
+    writerc.go yamlh.go yamlprivateh.go
+
+Copyright (c) 2006-2010 Kirill Simonov
+Copyright (c) 2006-2011 Kirill Simonov
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+of the Software, and to permit persons to whom the Software is furnished to do
+so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+
+### Apache License ###
+
+All the remaining project files are covered by the Apache license:
+
+Copyright (c) 2011-2019 Canonical Ltd
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
diff --git a/vendor/gopkg.in/yaml.v3/NOTICE b/vendor/gopkg.in/yaml.v3/NOTICE
new file mode 100644
index 000000000000..866d74a7ad79
--- /dev/null
+++ b/vendor/gopkg.in/yaml.v3/NOTICE
@@ -0,0 +1,13 @@
+Copyright 2011-2016 Canonical Ltd.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
diff --git a/vendor/gopkg.in/yaml.v3/README.md b/vendor/gopkg.in/yaml.v3/README.md
new file mode 100644
index 000000000000..08eb1babddfa
--- /dev/null
+++ b/vendor/gopkg.in/yaml.v3/README.md
@@ -0,0 +1,150 @@
+# YAML support for the Go language
+
+Introduction
+------------
+
+The yaml package enables Go programs to comfortably encode and decode YAML
+values. It was developed within [Canonical](https://www.canonical.com) as
+part of the [juju](https://juju.ubuntu.com) project, and is based on a
+pure Go port of the well-known [libyaml](http://pyyaml.org/wiki/LibYAML)
+C library to parse and generate YAML data quickly and reliably.
+
+Compatibility
+-------------
+
+The yaml package supports most of YAML 1.2, but preserves some behavior
+from 1.1 for backwards compatibility.
+
+Specifically, as of v3 of the yaml package:
+
+ - YAML 1.1 bools (_yes/no, on/off_) are supported as long as they are being
+   decoded into a typed bool value. Otherwise they behave as a string. Booleans
+   in YAML 1.2 are _true/false_ only.
+ - Octals encode and decode as _0777_ per YAML 1.1, rather than _0o777_
+   as specified in YAML 1.2, because most parsers still use the old format.
+   Octals in the  _0o777_ format are supported though, so new files work.
+ - Does not support base-60 floats. These are gone from YAML 1.2, and were
+   actually never supported by this package as it's clearly a poor choice.
+
+and offers backwards
+compatibility with YAML 1.1 in some cases.
+1.2, including support for
+anchors, tags, map merging, etc. Multi-document unmarshalling is not yet
+implemented, and base-60 floats from YAML 1.1 are purposefully not
+supported since they're a poor design and are gone in YAML 1.2.
+
+Installation and usage
+----------------------
+
+The import path for the package is *gopkg.in/yaml.v3*.
+
+To install it, run:
+
+    go get gopkg.in/yaml.v3
+
+API documentation
+-----------------
+
+If opened in a browser, the import path itself leads to the API documentation:
+
+  - [https://gopkg.in/yaml.v3](https://gopkg.in/yaml.v3)
+
+API stability
+-------------
+
+The package API for yaml v3 will remain stable as described in [gopkg.in](https://gopkg.in).
+
+
+License
+-------
+
+The yaml package is licensed under the MIT and Apache License 2.0 licenses.
+Please see the LICENSE file for details.
+
+
+Example
+-------
+
+```Go
+package main
+
+import (
+        "fmt"
+        "log"
+
+        "gopkg.in/yaml.v3"
+)
+
+var data = `
+a: Easy!
+b:
+  c: 2
+  d: [3, 4]
+`
+
+// Note: struct fields must be public in order for unmarshal to
+// correctly populate the data.
+type T struct {
+        A string
+        B struct {
+                RenamedC int   `yaml:"c"`
+                D        []int `yaml:",flow"`
+        }
+}
+
+func main() {
+        t := T{}
+    
+        err := yaml.Unmarshal([]byte(data), &t)
+        if err != nil {
+                log.Fatalf("error: %v", err)
+        }
+        fmt.Printf("--- t:\n%v\n\n", t)
+    
+        d, err := yaml.Marshal(&t)
+        if err != nil {
+                log.Fatalf("error: %v", err)
+        }
+        fmt.Printf("--- t dump:\n%s\n\n", string(d))
+    
+        m := make(map[interface{}]interface{})
+    
+        err = yaml.Unmarshal([]byte(data), &m)
+        if err != nil {
+                log.Fatalf("error: %v", err)
+        }
+        fmt.Printf("--- m:\n%v\n\n", m)
+    
+        d, err = yaml.Marshal(&m)
+        if err != nil {
+                log.Fatalf("error: %v", err)
+        }
+        fmt.Printf("--- m dump:\n%s\n\n", string(d))
+}
+```
+
+This example will generate the following output:
+
+```
+--- t:
+{Easy! {2 [3 4]}}
+
+--- t dump:
+a: Easy!
+b:
+  c: 2
+  d: [3, 4]
+
+
+--- m:
+map[a:Easy! b:map[c:2 d:[3 4]]]
+
+--- m dump:
+a: Easy!
+b:
+  c: 2
+  d:
+  - 3
+  - 4
+```
+
diff --git a/vendor/gopkg.in/yaml.v3/apic.go b/vendor/gopkg.in/yaml.v3/apic.go
new file mode 100644
index 000000000000..ae7d049f182a
--- /dev/null
+++ b/vendor/gopkg.in/yaml.v3/apic.go
@@ -0,0 +1,747 @@
+// 
+// Copyright (c) 2011-2019 Canonical Ltd
+// Copyright (c) 2006-2010 Kirill Simonov
+// 
+// Permission is hereby granted, free of charge, to any person obtaining a copy of
+// this software and associated documentation files (the "Software"), to deal in
+// the Software without restriction, including without limitation the rights to
+// use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+// of the Software, and to permit persons to whom the Software is furnished to do
+// so, subject to the following conditions:
+// 
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+// 
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+package yaml
+
+import (
+	"io"
+)
+
+func yaml_insert_token(parser *yaml_parser_t, pos int, token *yaml_token_t) {
+	//fmt.Println("yaml_insert_token", "pos:", pos, "typ:", token.typ, "head:", parser.tokens_head, "len:", len(parser.tokens))
+
+	// Check if we can move the queue at the beginning of the buffer.
+	if parser.tokens_head > 0 && len(parser.tokens) == cap(parser.tokens) {
+		if parser.tokens_head != len(parser.tokens) {
+			copy(parser.tokens, parser.tokens[parser.tokens_head:])
+		}
+		parser.tokens = parser.tokens[:len(parser.tokens)-parser.tokens_head]
+		parser.tokens_head = 0
+	}
+	parser.tokens = append(parser.tokens, *token)
+	if pos < 0 {
+		return
+	}
+	copy(parser.tokens[parser.tokens_head+pos+1:], parser.tokens[parser.tokens_head+pos:])
+	parser.tokens[parser.tokens_head+pos] = *token
+}
+
+// Create a new parser object.
+func yaml_parser_initialize(parser *yaml_parser_t) bool {
+	*parser = yaml_parser_t{
+		raw_buffer: make([]byte, 0, input_raw_buffer_size),
+		buffer:     make([]byte, 0, input_buffer_size),
+	}
+	return true
+}
+
+// Destroy a parser object.
+func yaml_parser_delete(parser *yaml_parser_t) {
+	*parser = yaml_parser_t{}
+}
+
+// String read handler.
+func yaml_string_read_handler(parser *yaml_parser_t, buffer []byte) (n int, err error) {
+	if parser.input_pos == len(parser.input) {
+		return 0, io.EOF
+	}
+	n = copy(buffer, parser.input[parser.input_pos:])
+	parser.input_pos += n
+	return n, nil
+}
+
+// Reader read handler.
+func yaml_reader_read_handler(parser *yaml_parser_t, buffer []byte) (n int, err error) {
+	return parser.input_reader.Read(buffer)
+}
+
+// Set a string input.
+func yaml_parser_set_input_string(parser *yaml_parser_t, input []byte) {
+	if parser.read_handler != nil {
+		panic("must set the input source only once")
+	}
+	parser.read_handler = yaml_string_read_handler
+	parser.input = input
+	parser.input_pos = 0
+}
+
+// Set a file input.
+func yaml_parser_set_input_reader(parser *yaml_parser_t, r io.Reader) {
+	if parser.read_handler != nil {
+		panic("must set the input source only once")
+	}
+	parser.read_handler = yaml_reader_read_handler
+	parser.input_reader = r
+}
+
+// Set the source encoding.
+func yaml_parser_set_encoding(parser *yaml_parser_t, encoding yaml_encoding_t) {
+	if parser.encoding != yaml_ANY_ENCODING {
+		panic("must set the encoding only once")
+	}
+	parser.encoding = encoding
+}
+
+// Create a new emitter object.
+func yaml_emitter_initialize(emitter *yaml_emitter_t) {
+	*emitter = yaml_emitter_t{
+		buffer:     make([]byte, output_buffer_size),
+		raw_buffer: make([]byte, 0, output_raw_buffer_size),
+		states:     make([]yaml_emitter_state_t, 0, initial_stack_size),
+		events:     make([]yaml_event_t, 0, initial_queue_size),
+		best_width: -1,
+	}
+}
+
+// Destroy an emitter object.
+func yaml_emitter_delete(emitter *yaml_emitter_t) {
+	*emitter = yaml_emitter_t{}
+}
+
+// String write handler.
+func yaml_string_write_handler(emitter *yaml_emitter_t, buffer []byte) error {
+	*emitter.output_buffer = append(*emitter.output_buffer, buffer...)
+	return nil
+}
+
+// yaml_writer_write_handler uses emitter.output_writer to write the
+// emitted text.
+func yaml_writer_write_handler(emitter *yaml_emitter_t, buffer []byte) error {
+	_, err := emitter.output_writer.Write(buffer)
+	return err
+}
+
+// Set a string output.
+func yaml_emitter_set_output_string(emitter *yaml_emitter_t, output_buffer *[]byte) {
+	if emitter.write_handler != nil {
+		panic("must set the output target only once")
+	}
+	emitter.write_handler = yaml_string_write_handler
+	emitter.output_buffer = output_buffer
+}
+
+// Set a file output.
+func yaml_emitter_set_output_writer(emitter *yaml_emitter_t, w io.Writer) {
+	if emitter.write_handler != nil {
+		panic("must set the output target only once")
+	}
+	emitter.write_handler = yaml_writer_write_handler
+	emitter.output_writer = w
+}
+
+// Set the output encoding.
+func yaml_emitter_set_encoding(emitter *yaml_emitter_t, encoding yaml_encoding_t) {
+	if emitter.encoding != yaml_ANY_ENCODING {
+		panic("must set the output encoding only once")
+	}
+	emitter.encoding = encoding
+}
+
+// Set the canonical output style.
+func yaml_emitter_set_canonical(emitter *yaml_emitter_t, canonical bool) {
+	emitter.canonical = canonical
+}
+
+// Set the indentation increment.
+func yaml_emitter_set_indent(emitter *yaml_emitter_t, indent int) {
+	if indent < 2 || indent > 9 {
+		indent = 2
+	}
+	emitter.best_indent = indent
+}
+
+// Set the preferred line width.
+func yaml_emitter_set_width(emitter *yaml_emitter_t, width int) {
+	if width < 0 {
+		width = -1
+	}
+	emitter.best_width = width
+}
+
+// Set if unescaped non-ASCII characters are allowed.
+func yaml_emitter_set_unicode(emitter *yaml_emitter_t, unicode bool) {
+	emitter.unicode = unicode
+}
+
+// Set the preferred line break character.
+func yaml_emitter_set_break(emitter *yaml_emitter_t, line_break yaml_break_t) {
+	emitter.line_break = line_break
+}
+
+///*
+// * Destroy a token object.
+// */
+//
+//YAML_DECLARE(void)
+//yaml_token_delete(yaml_token_t *token)
+//{
+//    assert(token);  // Non-NULL token object expected.
+//
+//    switch (token.type)
+//    {
+//        case YAML_TAG_DIRECTIVE_TOKEN:
+//            yaml_free(token.data.tag_directive.handle);
+//            yaml_free(token.data.tag_directive.prefix);
+//            break;
+//
+//        case YAML_ALIAS_TOKEN:
+//            yaml_free(token.data.alias.value);
+//            break;
+//
+//        case YAML_ANCHOR_TOKEN:
+//            yaml_free(token.data.anchor.value);
+//            break;
+//
+//        case YAML_TAG_TOKEN:
+//            yaml_free(token.data.tag.handle);
+//            yaml_free(token.data.tag.suffix);
+//            break;
+//
+//        case YAML_SCALAR_TOKEN:
+//            yaml_free(token.data.scalar.value);
+//            break;
+//
+//        default:
+//            break;
+//    }
+//
+//    memset(token, 0, sizeof(yaml_token_t));
+//}
+//
+///*
+// * Check if a string is a valid UTF-8 sequence.
+// *
+// * Check 'reader.c' for more details on UTF-8 encoding.
+// */
+//
+//static int
+//yaml_check_utf8(yaml_char_t *start, size_t length)
+//{
+//    yaml_char_t *end = start+length;
+//    yaml_char_t *pointer = start;
+//
+//    while (pointer < end) {
+//        unsigned char octet;
+//        unsigned int width;
+//        unsigned int value;
+//        size_t k;
+//
+//        octet = pointer[0];
+//        width = (octet & 0x80) == 0x00 ? 1 :
+//                (octet & 0xE0) == 0xC0 ? 2 :
+//                (octet & 0xF0) == 0xE0 ? 3 :
+//                (octet & 0xF8) == 0xF0 ? 4 : 0;
+//        value = (octet & 0x80) == 0x00 ? octet & 0x7F :
+//                (octet & 0xE0) == 0xC0 ? octet & 0x1F :
+//                (octet & 0xF0) == 0xE0 ? octet & 0x0F :
+//                (octet & 0xF8) == 0xF0 ? octet & 0x07 : 0;
+//        if (!width) return 0;
+//        if (pointer+width > end) return 0;
+//        for (k = 1; k < width; k ++) {
+//            octet = pointer[k];
+//            if ((octet & 0xC0) != 0x80) return 0;
+//            value = (value << 6) + (octet & 0x3F);
+//        }
+//        if (!((width == 1) ||
+//            (width == 2 && value >= 0x80) ||
+//            (width == 3 && value >= 0x800) ||
+//            (width == 4 && value >= 0x10000))) return 0;
+//
+//        pointer += width;
+//    }
+//
+//    return 1;
+//}
+//
+
+// Create STREAM-START.
+func yaml_stream_start_event_initialize(event *yaml_event_t, encoding yaml_encoding_t) {
+	*event = yaml_event_t{
+		typ:      yaml_STREAM_START_EVENT,
+		encoding: encoding,
+	}
+}
+
+// Create STREAM-END.
+func yaml_stream_end_event_initialize(event *yaml_event_t) {
+	*event = yaml_event_t{
+		typ: yaml_STREAM_END_EVENT,
+	}
+}
+
+// Create DOCUMENT-START.
+func yaml_document_start_event_initialize(
+	event *yaml_event_t,
+	version_directive *yaml_version_directive_t,
+	tag_directives []yaml_tag_directive_t,
+	implicit bool,
+) {
+	*event = yaml_event_t{
+		typ:               yaml_DOCUMENT_START_EVENT,
+		version_directive: version_directive,
+		tag_directives:    tag_directives,
+		implicit:          implicit,
+	}
+}
+
+// Create DOCUMENT-END.
+func yaml_document_end_event_initialize(event *yaml_event_t, implicit bool) {
+	*event = yaml_event_t{
+		typ:      yaml_DOCUMENT_END_EVENT,
+		implicit: implicit,
+	}
+}
+
+// Create ALIAS.
+func yaml_alias_event_initialize(event *yaml_event_t, anchor []byte) bool {
+	*event = yaml_event_t{
+		typ:    yaml_ALIAS_EVENT,
+		anchor: anchor,
+	}
+	return true
+}
+
+// Create SCALAR.
+func yaml_scalar_event_initialize(event *yaml_event_t, anchor, tag, value []byte, plain_implicit, quoted_implicit bool, style yaml_scalar_style_t) bool {
+	*event = yaml_event_t{
+		typ:             yaml_SCALAR_EVENT,
+		anchor:          anchor,
+		tag:             tag,
+		value:           value,
+		implicit:        plain_implicit,
+		quoted_implicit: quoted_implicit,
+		style:           yaml_style_t(style),
+	}
+	return true
+}
+
+// Create SEQUENCE-START.
+func yaml_sequence_start_event_initialize(event *yaml_event_t, anchor, tag []byte, implicit bool, style yaml_sequence_style_t) bool {
+	*event = yaml_event_t{
+		typ:      yaml_SEQUENCE_START_EVENT,
+		anchor:   anchor,
+		tag:      tag,
+		implicit: implicit,
+		style:    yaml_style_t(style),
+	}
+	return true
+}
+
+// Create SEQUENCE-END.
+func yaml_sequence_end_event_initialize(event *yaml_event_t) bool {
+	*event = yaml_event_t{
+		typ: yaml_SEQUENCE_END_EVENT,
+	}
+	return true
+}
+
+// Create MAPPING-START.
+func yaml_mapping_start_event_initialize(event *yaml_event_t, anchor, tag []byte, implicit bool, style yaml_mapping_style_t) {
+	*event = yaml_event_t{
+		typ:      yaml_MAPPING_START_EVENT,
+		anchor:   anchor,
+		tag:      tag,
+		implicit: implicit,
+		style:    yaml_style_t(style),
+	}
+}
+
+// Create MAPPING-END.
+func yaml_mapping_end_event_initialize(event *yaml_event_t) {
+	*event = yaml_event_t{
+		typ: yaml_MAPPING_END_EVENT,
+	}
+}
+
+// Destroy an event object.
+func yaml_event_delete(event *yaml_event_t) {
+	*event = yaml_event_t{}
+}
+
+///*
+// * Create a document object.
+// */
+//
+//YAML_DECLARE(int)
+//yaml_document_initialize(document *yaml_document_t,
+//        version_directive *yaml_version_directive_t,
+//        tag_directives_start *yaml_tag_directive_t,
+//        tag_directives_end *yaml_tag_directive_t,
+//        start_implicit int, end_implicit int)
+//{
+//    struct {
+//        error yaml_error_type_t
+//    } context
+//    struct {
+//        start *yaml_node_t
+//        end *yaml_node_t
+//        top *yaml_node_t
+//    } nodes = { NULL, NULL, NULL }
+//    version_directive_copy *yaml_version_directive_t = NULL
+//    struct {
+//        start *yaml_tag_directive_t
+//        end *yaml_tag_directive_t
+//        top *yaml_tag_directive_t
+//    } tag_directives_copy = { NULL, NULL, NULL }
+//    value yaml_tag_directive_t = { NULL, NULL }
+//    mark yaml_mark_t = { 0, 0, 0 }
+//
+//    assert(document) // Non-NULL document object is expected.
+//    assert((tag_directives_start && tag_directives_end) ||
+//            (tag_directives_start == tag_directives_end))
+//                            // Valid tag directives are expected.
+//
+//    if (!STACK_INIT(&context, nodes, INITIAL_STACK_SIZE)) goto error
+//
+//    if (version_directive) {
+//        version_directive_copy = yaml_malloc(sizeof(yaml_version_directive_t))
+//        if (!version_directive_copy) goto error
+//        version_directive_copy.major = version_directive.major
+//        version_directive_copy.minor = version_directive.minor
+//    }
+//
+//    if (tag_directives_start != tag_directives_end) {
+//        tag_directive *yaml_tag_directive_t
+//        if (!STACK_INIT(&context, tag_directives_copy, INITIAL_STACK_SIZE))
+//            goto error
+//        for (tag_directive = tag_directives_start
+//                tag_directive != tag_directives_end; tag_directive ++) {
+//            assert(tag_directive.handle)
+//            assert(tag_directive.prefix)
+//            if (!yaml_check_utf8(tag_directive.handle,
+//                        strlen((char *)tag_directive.handle)))
+//                goto error
+//            if (!yaml_check_utf8(tag_directive.prefix,
+//                        strlen((char *)tag_directive.prefix)))
+//                goto error
+//            value.handle = yaml_strdup(tag_directive.handle)
+//            value.prefix = yaml_strdup(tag_directive.prefix)
+//            if (!value.handle || !value.prefix) goto error
+//            if (!PUSH(&context, tag_directives_copy, value))
+//                goto error
+//            value.handle = NULL
+//            value.prefix = NULL
+//        }
+//    }
+//
+//    DOCUMENT_INIT(*document, nodes.start, nodes.end, version_directive_copy,
+//            tag_directives_copy.start, tag_directives_copy.top,
+//            start_implicit, end_implicit, mark, mark)
+//
+//    return 1
+//
+//error:
+//    STACK_DEL(&context, nodes)
+//    yaml_free(version_directive_copy)
+//    while (!STACK_EMPTY(&context, tag_directives_copy)) {
+//        value yaml_tag_directive_t = POP(&context, tag_directives_copy)
+//        yaml_free(value.handle)
+//        yaml_free(value.prefix)
+//    }
+//    STACK_DEL(&context, tag_directives_copy)
+//    yaml_free(value.handle)
+//    yaml_free(value.prefix)
+//
+//    return 0
+//}
+//
+///*
+// * Destroy a document object.
+// */
+//
+//YAML_DECLARE(void)
+//yaml_document_delete(document *yaml_document_t)
+//{
+//    struct {
+//        error yaml_error_type_t
+//    } context
+//    tag_directive *yaml_tag_directive_t
+//
+//    context.error = YAML_NO_ERROR // Eliminate a compiler warning.
+//
+//    assert(document) // Non-NULL document object is expected.
+//
+//    while (!STACK_EMPTY(&context, document.nodes)) {
+//        node yaml_node_t = POP(&context, document.nodes)
+//        yaml_free(node.tag)
+//        switch (node.type) {
+//            case YAML_SCALAR_NODE:
+//                yaml_free(node.data.scalar.value)
+//                break
+//            case YAML_SEQUENCE_NODE:
+//                STACK_DEL(&context, node.data.sequence.items)
+//                break
+//            case YAML_MAPPING_NODE:
+//                STACK_DEL(&context, node.data.mapping.pairs)
+//                break
+//            default:
+//                assert(0) // Should not happen.
+//        }
+//    }
+//    STACK_DEL(&context, document.nodes)
+//
+//    yaml_free(document.version_directive)
+//    for (tag_directive = document.tag_directives.start
+//            tag_directive != document.tag_directives.end
+//            tag_directive++) {
+//        yaml_free(tag_directive.handle)
+//        yaml_free(tag_directive.prefix)
+//    }
+//    yaml_free(document.tag_directives.start)
+//
+//    memset(document, 0, sizeof(yaml_document_t))
+//}
+//
+///**
+// * Get a document node.
+// */
+//
+//YAML_DECLARE(yaml_node_t *)
+//yaml_document_get_node(document *yaml_document_t, index int)
+//{
+//    assert(document) // Non-NULL document object is expected.
+//
+//    if (index > 0 && document.nodes.start + index <= document.nodes.top) {
+//        return document.nodes.start + index - 1
+//    }
+//    return NULL
+//}
+//
+///**
+// * Get the root object.
+// */
+//
+//YAML_DECLARE(yaml_node_t *)
+//yaml_document_get_root_node(document *yaml_document_t)
+//{
+//    assert(document) // Non-NULL document object is expected.
+//
+//    if (document.nodes.top != document.nodes.start) {
+//        return document.nodes.start
+//    }
+//    return NULL
+//}
+//
+///*
+// * Add a scalar node to a document.
+// */
+//
+//YAML_DECLARE(int)
+//yaml_document_add_scalar(document *yaml_document_t,
+//        tag *yaml_char_t, value *yaml_char_t, length int,
+//        style yaml_scalar_style_t)
+//{
+//    struct {
+//        error yaml_error_type_t
+//    } context
+//    mark yaml_mark_t = { 0, 0, 0 }
+//    tag_copy *yaml_char_t = NULL
+//    value_copy *yaml_char_t = NULL
+//    node yaml_node_t
+//
+//    assert(document) // Non-NULL document object is expected.
+//    assert(value) // Non-NULL value is expected.
+//
+//    if (!tag) {
+//        tag = (yaml_char_t *)YAML_DEFAULT_SCALAR_TAG
+//    }
+//
+//    if (!yaml_check_utf8(tag, strlen((char *)tag))) goto error
+//    tag_copy = yaml_strdup(tag)
+//    if (!tag_copy) goto error
+//
+//    if (length < 0) {
+//        length = strlen((char *)value)
+//    }
+//
+//    if (!yaml_check_utf8(value, length)) goto error
+//    value_copy = yaml_malloc(length+1)
+//    if (!value_copy) goto error
+//    memcpy(value_copy, value, length)
+//    value_copy[length] = '\0'
+//
+//    SCALAR_NODE_INIT(node, tag_copy, value_copy, length, style, mark, mark)
+//    if (!PUSH(&context, document.nodes, node)) goto error
+//
+//    return document.nodes.top - document.nodes.start
+//
+//error:
+//    yaml_free(tag_copy)
+//    yaml_free(value_copy)
+//
+//    return 0
+//}
+//
+///*
+// * Add a sequence node to a document.
+// */
+//
+//YAML_DECLARE(int)
+//yaml_document_add_sequence(document *yaml_document_t,
+//        tag *yaml_char_t, style yaml_sequence_style_t)
+//{
+//    struct {
+//        error yaml_error_type_t
+//    } context
+//    mark yaml_mark_t = { 0, 0, 0 }
+//    tag_copy *yaml_char_t = NULL
+//    struct {
+//        start *yaml_node_item_t
+//        end *yaml_node_item_t
+//        top *yaml_node_item_t
+//    } items = { NULL, NULL, NULL }
+//    node yaml_node_t
+//
+//    assert(document) // Non-NULL document object is expected.
+//
+//    if (!tag) {
+//        tag = (yaml_char_t *)YAML_DEFAULT_SEQUENCE_TAG
+//    }
+//
+//    if (!yaml_check_utf8(tag, strlen((char *)tag))) goto error
+//    tag_copy = yaml_strdup(tag)
+//    if (!tag_copy) goto error
+//
+//    if (!STACK_INIT(&context, items, INITIAL_STACK_SIZE)) goto error
+//
+//    SEQUENCE_NODE_INIT(node, tag_copy, items.start, items.end,
+//            style, mark, mark)
+//    if (!PUSH(&context, document.nodes, node)) goto error
+//
+//    return document.nodes.top - document.nodes.start
+//
+//error:
+//    STACK_DEL(&context, items)
+//    yaml_free(tag_copy)
+//
+//    return 0
+//}
+//
+///*
+// * Add a mapping node to a document.
+// */
+//
+//YAML_DECLARE(int)
+//yaml_document_add_mapping(document *yaml_document_t,
+//        tag *yaml_char_t, style yaml_mapping_style_t)
+//{
+//    struct {
+//        error yaml_error_type_t
+//    } context
+//    mark yaml_mark_t = { 0, 0, 0 }
+//    tag_copy *yaml_char_t = NULL
+//    struct {
+//        start *yaml_node_pair_t
+//        end *yaml_node_pair_t
+//        top *yaml_node_pair_t
+//    } pairs = { NULL, NULL, NULL }
+//    node yaml_node_t
+//
+//    assert(document) // Non-NULL document object is expected.
+//
+//    if (!tag) {
+//        tag = (yaml_char_t *)YAML_DEFAULT_MAPPING_TAG
+//    }
+//
+//    if (!yaml_check_utf8(tag, strlen((char *)tag))) goto error
+//    tag_copy = yaml_strdup(tag)
+//    if (!tag_copy) goto error
+//
+//    if (!STACK_INIT(&context, pairs, INITIAL_STACK_SIZE)) goto error
+//
+//    MAPPING_NODE_INIT(node, tag_copy, pairs.start, pairs.end,
+//            style, mark, mark)
+//    if (!PUSH(&context, document.nodes, node)) goto error
+//
+//    return document.nodes.top - document.nodes.start
+//
+//error:
+//    STACK_DEL(&context, pairs)
+//    yaml_free(tag_copy)
+//
+//    return 0
+//}
+//
+///*
+// * Append an item to a sequence node.
+// */
+//
+//YAML_DECLARE(int)
+//yaml_document_append_sequence_item(document *yaml_document_t,
+//        sequence int, item int)
+//{
+//    struct {
+//        error yaml_error_type_t
+//    } context
+//
+//    assert(document) // Non-NULL document is required.
+//    assert(sequence > 0
+//            && document.nodes.start + sequence <= document.nodes.top)
+//                            // Valid sequence id is required.
+//    assert(document.nodes.start[sequence-1].type == YAML_SEQUENCE_NODE)
+//                            // A sequence node is required.
+//    assert(item > 0 && document.nodes.start + item <= document.nodes.top)
+//                            // Valid item id is required.
+//
+//    if (!PUSH(&context,
+//                document.nodes.start[sequence-1].data.sequence.items, item))
+//        return 0
+//
+//    return 1
+//}
+//
+///*
+// * Append a pair of a key and a value to a mapping node.
+// */
+//
+//YAML_DECLARE(int)
+//yaml_document_append_mapping_pair(document *yaml_document_t,
+//        mapping int, key int, value int)
+//{
+//    struct {
+//        error yaml_error_type_t
+//    } context
+//
+//    pair yaml_node_pair_t
+//
+//    assert(document) // Non-NULL document is required.
+//    assert(mapping > 0
+//            && document.nodes.start + mapping <= document.nodes.top)
+//                            // Valid mapping id is required.
+//    assert(document.nodes.start[mapping-1].type == YAML_MAPPING_NODE)
+//                            // A mapping node is required.
+//    assert(key > 0 && document.nodes.start + key <= document.nodes.top)
+//                            // Valid key id is required.
+//    assert(value > 0 && document.nodes.start + value <= document.nodes.top)
+//                            // Valid value id is required.
+//
+//    pair.key = key
+//    pair.value = value
+//
+//    if (!PUSH(&context,
+//                document.nodes.start[mapping-1].data.mapping.pairs, pair))
+//        return 0
+//
+//    return 1
+//}
+//
+//
diff --git a/vendor/gopkg.in/yaml.v3/decode.go b/vendor/gopkg.in/yaml.v3/decode.go
new file mode 100644
index 000000000000..0173b6982e84
--- /dev/null
+++ b/vendor/gopkg.in/yaml.v3/decode.go
@@ -0,0 +1,1000 @@
+//
+// Copyright (c) 2011-2019 Canonical Ltd
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package yaml
+
+import (
+	"encoding"
+	"encoding/base64"
+	"fmt"
+	"io"
+	"math"
+	"reflect"
+	"strconv"
+	"time"
+)
+
+// ----------------------------------------------------------------------------
+// Parser, produces a node tree out of a libyaml event stream.
+
+type parser struct {
+	parser   yaml_parser_t
+	event    yaml_event_t
+	doc      *Node
+	anchors  map[string]*Node
+	doneInit bool
+	textless bool
+}
+
+func newParser(b []byte) *parser {
+	p := parser{}
+	if !yaml_parser_initialize(&p.parser) {
+		panic("failed to initialize YAML emitter")
+	}
+	if len(b) == 0 {
+		b = []byte{'\n'}
+	}
+	yaml_parser_set_input_string(&p.parser, b)
+	return &p
+}
+
+func newParserFromReader(r io.Reader) *parser {
+	p := parser{}
+	if !yaml_parser_initialize(&p.parser) {
+		panic("failed to initialize YAML emitter")
+	}
+	yaml_parser_set_input_reader(&p.parser, r)
+	return &p
+}
+
+func (p *parser) init() {
+	if p.doneInit {
+		return
+	}
+	p.anchors = make(map[string]*Node)
+	p.expect(yaml_STREAM_START_EVENT)
+	p.doneInit = true
+}
+
+func (p *parser) destroy() {
+	if p.event.typ != yaml_NO_EVENT {
+		yaml_event_delete(&p.event)
+	}
+	yaml_parser_delete(&p.parser)
+}
+
+// expect consumes an event from the event stream and
+// checks that it's of the expected type.
+func (p *parser) expect(e yaml_event_type_t) {
+	if p.event.typ == yaml_NO_EVENT {
+		if !yaml_parser_parse(&p.parser, &p.event) {
+			p.fail()
+		}
+	}
+	if p.event.typ == yaml_STREAM_END_EVENT {
+		failf("attempted to go past the end of stream; corrupted value?")
+	}
+	if p.event.typ != e {
+		p.parser.problem = fmt.Sprintf("expected %s event but got %s", e, p.event.typ)
+		p.fail()
+	}
+	yaml_event_delete(&p.event)
+	p.event.typ = yaml_NO_EVENT
+}
+
+// peek peeks at the next event in the event stream,
+// puts the results into p.event and returns the event type.
+func (p *parser) peek() yaml_event_type_t {
+	if p.event.typ != yaml_NO_EVENT {
+		return p.event.typ
+	}
+	// It's curious choice from the underlying API to generally return a
+	// positive result on success, but on this case return true in an error
+	// scenario. This was the source of bugs in the past (issue #666).
+	if !yaml_parser_parse(&p.parser, &p.event) || p.parser.error != yaml_NO_ERROR {
+		p.fail()
+	}
+	return p.event.typ
+}
+
+func (p *parser) fail() {
+	var where string
+	var line int
+	if p.parser.context_mark.line != 0 {
+		line = p.parser.context_mark.line
+		// Scanner errors don't iterate line before returning error
+		if p.parser.error == yaml_SCANNER_ERROR {
+			line++
+		}
+	} else if p.parser.problem_mark.line != 0 {
+		line = p.parser.problem_mark.line
+		// Scanner errors don't iterate line before returning error
+		if p.parser.error == yaml_SCANNER_ERROR {
+			line++
+		}
+	}
+	if line != 0 {
+		where = "line " + strconv.Itoa(line) + ": "
+	}
+	var msg string
+	if len(p.parser.problem) > 0 {
+		msg = p.parser.problem
+	} else {
+		msg = "unknown problem parsing YAML content"
+	}
+	failf("%s%s", where, msg)
+}
+
+func (p *parser) anchor(n *Node, anchor []byte) {
+	if anchor != nil {
+		n.Anchor = string(anchor)
+		p.anchors[n.Anchor] = n
+	}
+}
+
+func (p *parser) parse() *Node {
+	p.init()
+	switch p.peek() {
+	case yaml_SCALAR_EVENT:
+		return p.scalar()
+	case yaml_ALIAS_EVENT:
+		return p.alias()
+	case yaml_MAPPING_START_EVENT:
+		return p.mapping()
+	case yaml_SEQUENCE_START_EVENT:
+		return p.sequence()
+	case yaml_DOCUMENT_START_EVENT:
+		return p.document()
+	case yaml_STREAM_END_EVENT:
+		// Happens when attempting to decode an empty buffer.
+		return nil
+	case yaml_TAIL_COMMENT_EVENT:
+		panic("internal error: unexpected tail comment event (please report)")
+	default:
+		panic("internal error: attempted to parse unknown event (please report): " + p.event.typ.String())
+	}
+}
+
+func (p *parser) node(kind Kind, defaultTag, tag, value string) *Node {
+	var style Style
+	if tag != "" && tag != "!" {
+		tag = shortTag(tag)
+		style = TaggedStyle
+	} else if defaultTag != "" {
+		tag = defaultTag
+	} else if kind == ScalarNode {
+		tag, _ = resolve("", value)
+	}
+	n := &Node{
+		Kind:  kind,
+		Tag:   tag,
+		Value: value,
+		Style: style,
+	}
+	if !p.textless {
+		n.Line = p.event.start_mark.line + 1
+		n.Column = p.event.start_mark.column + 1
+		n.HeadComment = string(p.event.head_comment)
+		n.LineComment = string(p.event.line_comment)
+		n.FootComment = string(p.event.foot_comment)
+	}
+	return n
+}
+
+func (p *parser) parseChild(parent *Node) *Node {
+	child := p.parse()
+	parent.Content = append(parent.Content, child)
+	return child
+}
+
+func (p *parser) document() *Node {
+	n := p.node(DocumentNode, "", "", "")
+	p.doc = n
+	p.expect(yaml_DOCUMENT_START_EVENT)
+	p.parseChild(n)
+	if p.peek() == yaml_DOCUMENT_END_EVENT {
+		n.FootComment = string(p.event.foot_comment)
+	}
+	p.expect(yaml_DOCUMENT_END_EVENT)
+	return n
+}
+
+func (p *parser) alias() *Node {
+	n := p.node(AliasNode, "", "", string(p.event.anchor))
+	n.Alias = p.anchors[n.Value]
+	if n.Alias == nil {
+		failf("unknown anchor '%s' referenced", n.Value)
+	}
+	p.expect(yaml_ALIAS_EVENT)
+	return n
+}
+
+func (p *parser) scalar() *Node {
+	var parsedStyle = p.event.scalar_style()
+	var nodeStyle Style
+	switch {
+	case parsedStyle&yaml_DOUBLE_QUOTED_SCALAR_STYLE != 0:
+		nodeStyle = DoubleQuotedStyle
+	case parsedStyle&yaml_SINGLE_QUOTED_SCALAR_STYLE != 0:
+		nodeStyle = SingleQuotedStyle
+	case parsedStyle&yaml_LITERAL_SCALAR_STYLE != 0:
+		nodeStyle = LiteralStyle
+	case parsedStyle&yaml_FOLDED_SCALAR_STYLE != 0:
+		nodeStyle = FoldedStyle
+	}
+	var nodeValue = string(p.event.value)
+	var nodeTag = string(p.event.tag)
+	var defaultTag string
+	if nodeStyle == 0 {
+		if nodeValue == "<<" {
+			defaultTag = mergeTag
+		}
+	} else {
+		defaultTag = strTag
+	}
+	n := p.node(ScalarNode, defaultTag, nodeTag, nodeValue)
+	n.Style |= nodeStyle
+	p.anchor(n, p.event.anchor)
+	p.expect(yaml_SCALAR_EVENT)
+	return n
+}
+
+func (p *parser) sequence() *Node {
+	n := p.node(SequenceNode, seqTag, string(p.event.tag), "")
+	if p.event.sequence_style()&yaml_FLOW_SEQUENCE_STYLE != 0 {
+		n.Style |= FlowStyle
+	}
+	p.anchor(n, p.event.anchor)
+	p.expect(yaml_SEQUENCE_START_EVENT)
+	for p.peek() != yaml_SEQUENCE_END_EVENT {
+		p.parseChild(n)
+	}
+	n.LineComment = string(p.event.line_comment)
+	n.FootComment = string(p.event.foot_comment)
+	p.expect(yaml_SEQUENCE_END_EVENT)
+	return n
+}
+
+func (p *parser) mapping() *Node {
+	n := p.node(MappingNode, mapTag, string(p.event.tag), "")
+	block := true
+	if p.event.mapping_style()&yaml_FLOW_MAPPING_STYLE != 0 {
+		block = false
+		n.Style |= FlowStyle
+	}
+	p.anchor(n, p.event.anchor)
+	p.expect(yaml_MAPPING_START_EVENT)
+	for p.peek() != yaml_MAPPING_END_EVENT {
+		k := p.parseChild(n)
+		if block && k.FootComment != "" {
+			// Must be a foot comment for the prior value when being dedented.
+			if len(n.Content) > 2 {
+				n.Content[len(n.Content)-3].FootComment = k.FootComment
+				k.FootComment = ""
+			}
+		}
+		v := p.parseChild(n)
+		if k.FootComment == "" && v.FootComment != "" {
+			k.FootComment = v.FootComment
+			v.FootComment = ""
+		}
+		if p.peek() == yaml_TAIL_COMMENT_EVENT {
+			if k.FootComment == "" {
+				k.FootComment = string(p.event.foot_comment)
+			}
+			p.expect(yaml_TAIL_COMMENT_EVENT)
+		}
+	}
+	n.LineComment = string(p.event.line_comment)
+	n.FootComment = string(p.event.foot_comment)
+	if n.Style&FlowStyle == 0 && n.FootComment != "" && len(n.Content) > 1 {
+		n.Content[len(n.Content)-2].FootComment = n.FootComment
+		n.FootComment = ""
+	}
+	p.expect(yaml_MAPPING_END_EVENT)
+	return n
+}
+
+// ----------------------------------------------------------------------------
+// Decoder, unmarshals a node into a provided value.
+
+type decoder struct {
+	doc     *Node
+	aliases map[*Node]bool
+	terrors []string
+
+	stringMapType  reflect.Type
+	generalMapType reflect.Type
+
+	knownFields bool
+	uniqueKeys  bool
+	decodeCount int
+	aliasCount  int
+	aliasDepth  int
+
+	mergedFields map[interface{}]bool
+}
+
+var (
+	nodeType       = reflect.TypeOf(Node{})
+	durationType   = reflect.TypeOf(time.Duration(0))
+	stringMapType  = reflect.TypeOf(map[string]interface{}{})
+	generalMapType = reflect.TypeOf(map[interface{}]interface{}{})
+	ifaceType      = generalMapType.Elem()
+	timeType       = reflect.TypeOf(time.Time{})
+	ptrTimeType    = reflect.TypeOf(&time.Time{})
+)
+
+func newDecoder() *decoder {
+	d := &decoder{
+		stringMapType:  stringMapType,
+		generalMapType: generalMapType,
+		uniqueKeys:     true,
+	}
+	d.aliases = make(map[*Node]bool)
+	return d
+}
+
+func (d *decoder) terror(n *Node, tag string, out reflect.Value) {
+	if n.Tag != "" {
+		tag = n.Tag
+	}
+	value := n.Value
+	if tag != seqTag && tag != mapTag {
+		if len(value) > 10 {
+			value = " `" + value[:7] + "...`"
+		} else {
+			value = " `" + value + "`"
+		}
+	}
+	d.terrors = append(d.terrors, fmt.Sprintf("line %d: cannot unmarshal %s%s into %s", n.Line, shortTag(tag), value, out.Type()))
+}
+
+func (d *decoder) callUnmarshaler(n *Node, u Unmarshaler) (good bool) {
+	err := u.UnmarshalYAML(n)
+	if e, ok := err.(*TypeError); ok {
+		d.terrors = append(d.terrors, e.Errors...)
+		return false
+	}
+	if err != nil {
+		fail(err)
+	}
+	return true
+}
+
+func (d *decoder) callObsoleteUnmarshaler(n *Node, u obsoleteUnmarshaler) (good bool) {
+	terrlen := len(d.terrors)
+	err := u.UnmarshalYAML(func(v interface{}) (err error) {
+		defer handleErr(&err)
+		d.unmarshal(n, reflect.ValueOf(v))
+		if len(d.terrors) > terrlen {
+			issues := d.terrors[terrlen:]
+			d.terrors = d.terrors[:terrlen]
+			return &TypeError{issues}
+		}
+		return nil
+	})
+	if e, ok := err.(*TypeError); ok {
+		d.terrors = append(d.terrors, e.Errors...)
+		return false
+	}
+	if err != nil {
+		fail(err)
+	}
+	return true
+}
+
+// d.prepare initializes and dereferences pointers and calls UnmarshalYAML
+// if a value is found to implement it.
+// It returns the initialized and dereferenced out value, whether
+// unmarshalling was already done by UnmarshalYAML, and if so whether
+// its types unmarshalled appropriately.
+//
+// If n holds a null value, prepare returns before doing anything.
+func (d *decoder) prepare(n *Node, out reflect.Value) (newout reflect.Value, unmarshaled, good bool) {
+	if n.ShortTag() == nullTag {
+		return out, false, false
+	}
+	again := true
+	for again {
+		again = false
+		if out.Kind() == reflect.Ptr {
+			if out.IsNil() {
+				out.Set(reflect.New(out.Type().Elem()))
+			}
+			out = out.Elem()
+			again = true
+		}
+		if out.CanAddr() {
+			outi := out.Addr().Interface()
+			if u, ok := outi.(Unmarshaler); ok {
+				good = d.callUnmarshaler(n, u)
+				return out, true, good
+			}
+			if u, ok := outi.(obsoleteUnmarshaler); ok {
+				good = d.callObsoleteUnmarshaler(n, u)
+				return out, true, good
+			}
+		}
+	}
+	return out, false, false
+}
+
+func (d *decoder) fieldByIndex(n *Node, v reflect.Value, index []int) (field reflect.Value) {
+	if n.ShortTag() == nullTag {
+		return reflect.Value{}
+	}
+	for _, num := range index {
+		for {
+			if v.Kind() == reflect.Ptr {
+				if v.IsNil() {
+					v.Set(reflect.New(v.Type().Elem()))
+				}
+				v = v.Elem()
+				continue
+			}
+			break
+		}
+		v = v.Field(num)
+	}
+	return v
+}
+
+const (
+	// 400,000 decode operations is ~500kb of dense object declarations, or
+	// ~5kb of dense object declarations with 10000% alias expansion
+	alias_ratio_range_low = 400000
+
+	// 4,000,000 decode operations is ~5MB of dense object declarations, or
+	// ~4.5MB of dense object declarations with 10% alias expansion
+	alias_ratio_range_high = 4000000
+
+	// alias_ratio_range is the range over which we scale allowed alias ratios
+	alias_ratio_range = float64(alias_ratio_range_high - alias_ratio_range_low)
+)
+
+func allowedAliasRatio(decodeCount int) float64 {
+	switch {
+	case decodeCount <= alias_ratio_range_low:
+		// allow 99% to come from alias expansion for small-to-medium documents
+		return 0.99
+	case decodeCount >= alias_ratio_range_high:
+		// allow 10% to come from alias expansion for very large documents
+		return 0.10
+	default:
+		// scale smoothly from 99% down to 10% over the range.
+		// this maps to 396,000 - 400,000 allowed alias-driven decodes over the range.
+		// 400,000 decode operations is ~100MB of allocations in worst-case scenarios (single-item maps).
+		return 0.99 - 0.89*(float64(decodeCount-alias_ratio_range_low)/alias_ratio_range)
+	}
+}
+
+func (d *decoder) unmarshal(n *Node, out reflect.Value) (good bool) {
+	d.decodeCount++
+	if d.aliasDepth > 0 {
+		d.aliasCount++
+	}
+	if d.aliasCount > 100 && d.decodeCount > 1000 && float64(d.aliasCount)/float64(d.decodeCount) > allowedAliasRatio(d.decodeCount) {
+		failf("document contains excessive aliasing")
+	}
+	if out.Type() == nodeType {
+		out.Set(reflect.ValueOf(n).Elem())
+		return true
+	}
+	switch n.Kind {
+	case DocumentNode:
+		return d.document(n, out)
+	case AliasNode:
+		return d.alias(n, out)
+	}
+	out, unmarshaled, good := d.prepare(n, out)
+	if unmarshaled {
+		return good
+	}
+	switch n.Kind {
+	case ScalarNode:
+		good = d.scalar(n, out)
+	case MappingNode:
+		good = d.mapping(n, out)
+	case SequenceNode:
+		good = d.sequence(n, out)
+	case 0:
+		if n.IsZero() {
+			return d.null(out)
+		}
+		fallthrough
+	default:
+		failf("cannot decode node with unknown kind %d", n.Kind)
+	}
+	return good
+}
+
+func (d *decoder) document(n *Node, out reflect.Value) (good bool) {
+	if len(n.Content) == 1 {
+		d.doc = n
+		d.unmarshal(n.Content[0], out)
+		return true
+	}
+	return false
+}
+
+func (d *decoder) alias(n *Node, out reflect.Value) (good bool) {
+	if d.aliases[n] {
+		// TODO this could actually be allowed in some circumstances.
+		failf("anchor '%s' value contains itself", n.Value)
+	}
+	d.aliases[n] = true
+	d.aliasDepth++
+	good = d.unmarshal(n.Alias, out)
+	d.aliasDepth--
+	delete(d.aliases, n)
+	return good
+}
+
+var zeroValue reflect.Value
+
+func resetMap(out reflect.Value) {
+	for _, k := range out.MapKeys() {
+		out.SetMapIndex(k, zeroValue)
+	}
+}
+
+func (d *decoder) null(out reflect.Value) bool {
+	if out.CanAddr() {
+		switch out.Kind() {
+		case reflect.Interface, reflect.Ptr, reflect.Map, reflect.Slice:
+			out.Set(reflect.Zero(out.Type()))
+			return true
+		}
+	}
+	return false
+}
+
+func (d *decoder) scalar(n *Node, out reflect.Value) bool {
+	var tag string
+	var resolved interface{}
+	if n.indicatedString() {
+		tag = strTag
+		resolved = n.Value
+	} else {
+		tag, resolved = resolve(n.Tag, n.Value)
+		if tag == binaryTag {
+			data, err := base64.StdEncoding.DecodeString(resolved.(string))
+			if err != nil {
+				failf("!!binary value contains invalid base64 data")
+			}
+			resolved = string(data)
+		}
+	}
+	if resolved == nil {
+		return d.null(out)
+	}
+	if resolvedv := reflect.ValueOf(resolved); out.Type() == resolvedv.Type() {
+		// We've resolved to exactly the type we want, so use that.
+		out.Set(resolvedv)
+		return true
+	}
+	// Perhaps we can use the value as a TextUnmarshaler to
+	// set its value.
+	if out.CanAddr() {
+		u, ok := out.Addr().Interface().(encoding.TextUnmarshaler)
+		if ok {
+			var text []byte
+			if tag == binaryTag {
+				text = []byte(resolved.(string))
+			} else {
+				// We let any value be unmarshaled into TextUnmarshaler.
+				// That might be more lax than we'd like, but the
+				// TextUnmarshaler itself should bowl out any dubious values.
+				text = []byte(n.Value)
+			}
+			err := u.UnmarshalText(text)
+			if err != nil {
+				fail(err)
+			}
+			return true
+		}
+	}
+	switch out.Kind() {
+	case reflect.String:
+		if tag == binaryTag {
+			out.SetString(resolved.(string))
+			return true
+		}
+		out.SetString(n.Value)
+		return true
+	case reflect.Interface:
+		out.Set(reflect.ValueOf(resolved))
+		return true
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		// This used to work in v2, but it's very unfriendly.
+		isDuration := out.Type() == durationType
+
+		switch resolved := resolved.(type) {
+		case int:
+			if !isDuration && !out.OverflowInt(int64(resolved)) {
+				out.SetInt(int64(resolved))
+				return true
+			}
+		case int64:
+			if !isDuration && !out.OverflowInt(resolved) {
+				out.SetInt(resolved)
+				return true
+			}
+		case uint64:
+			if !isDuration && resolved <= math.MaxInt64 && !out.OverflowInt(int64(resolved)) {
+				out.SetInt(int64(resolved))
+				return true
+			}
+		case float64:
+			if !isDuration && resolved <= math.MaxInt64 && !out.OverflowInt(int64(resolved)) {
+				out.SetInt(int64(resolved))
+				return true
+			}
+		case string:
+			if out.Type() == durationType {
+				d, err := time.ParseDuration(resolved)
+				if err == nil {
+					out.SetInt(int64(d))
+					return true
+				}
+			}
+		}
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+		switch resolved := resolved.(type) {
+		case int:
+			if resolved >= 0 && !out.OverflowUint(uint64(resolved)) {
+				out.SetUint(uint64(resolved))
+				return true
+			}
+		case int64:
+			if resolved >= 0 && !out.OverflowUint(uint64(resolved)) {
+				out.SetUint(uint64(resolved))
+				return true
+			}
+		case uint64:
+			if !out.OverflowUint(uint64(resolved)) {
+				out.SetUint(uint64(resolved))
+				return true
+			}
+		case float64:
+			if resolved <= math.MaxUint64 && !out.OverflowUint(uint64(resolved)) {
+				out.SetUint(uint64(resolved))
+				return true
+			}
+		}
+	case reflect.Bool:
+		switch resolved := resolved.(type) {
+		case bool:
+			out.SetBool(resolved)
+			return true
+		case string:
+			// This offers some compatibility with the 1.1 spec (https://yaml.org/type/bool.html).
+			// It only works if explicitly attempting to unmarshal into a typed bool value.
+			switch resolved {
+			case "y", "Y", "yes", "Yes", "YES", "on", "On", "ON":
+				out.SetBool(true)
+				return true
+			case "n", "N", "no", "No", "NO", "off", "Off", "OFF":
+				out.SetBool(false)
+				return true
+			}
+		}
+	case reflect.Float32, reflect.Float64:
+		switch resolved := resolved.(type) {
+		case int:
+			out.SetFloat(float64(resolved))
+			return true
+		case int64:
+			out.SetFloat(float64(resolved))
+			return true
+		case uint64:
+			out.SetFloat(float64(resolved))
+			return true
+		case float64:
+			out.SetFloat(resolved)
+			return true
+		}
+	case reflect.Struct:
+		if resolvedv := reflect.ValueOf(resolved); out.Type() == resolvedv.Type() {
+			out.Set(resolvedv)
+			return true
+		}
+	case reflect.Ptr:
+		panic("yaml internal error: please report the issue")
+	}
+	d.terror(n, tag, out)
+	return false
+}
+
+func settableValueOf(i interface{}) reflect.Value {
+	v := reflect.ValueOf(i)
+	sv := reflect.New(v.Type()).Elem()
+	sv.Set(v)
+	return sv
+}
+
+func (d *decoder) sequence(n *Node, out reflect.Value) (good bool) {
+	l := len(n.Content)
+
+	var iface reflect.Value
+	switch out.Kind() {
+	case reflect.Slice:
+		out.Set(reflect.MakeSlice(out.Type(), l, l))
+	case reflect.Array:
+		if l != out.Len() {
+			failf("invalid array: want %d elements but got %d", out.Len(), l)
+		}
+	case reflect.Interface:
+		// No type hints. Will have to use a generic sequence.
+		iface = out
+		out = settableValueOf(make([]interface{}, l))
+	default:
+		d.terror(n, seqTag, out)
+		return false
+	}
+	et := out.Type().Elem()
+
+	j := 0
+	for i := 0; i < l; i++ {
+		e := reflect.New(et).Elem()
+		if ok := d.unmarshal(n.Content[i], e); ok {
+			out.Index(j).Set(e)
+			j++
+		}
+	}
+	if out.Kind() != reflect.Array {
+		out.Set(out.Slice(0, j))
+	}
+	if iface.IsValid() {
+		iface.Set(out)
+	}
+	return true
+}
+
+func (d *decoder) mapping(n *Node, out reflect.Value) (good bool) {
+	l := len(n.Content)
+	if d.uniqueKeys {
+		nerrs := len(d.terrors)
+		for i := 0; i < l; i += 2 {
+			ni := n.Content[i]
+			for j := i + 2; j < l; j += 2 {
+				nj := n.Content[j]
+				if ni.Kind == nj.Kind && ni.Value == nj.Value {
+					d.terrors = append(d.terrors, fmt.Sprintf("line %d: mapping key %#v already defined at line %d", nj.Line, nj.Value, ni.Line))
+				}
+			}
+		}
+		if len(d.terrors) > nerrs {
+			return false
+		}
+	}
+	switch out.Kind() {
+	case reflect.Struct:
+		return d.mappingStruct(n, out)
+	case reflect.Map:
+		// okay
+	case reflect.Interface:
+		iface := out
+		if isStringMap(n) {
+			out = reflect.MakeMap(d.stringMapType)
+		} else {
+			out = reflect.MakeMap(d.generalMapType)
+		}
+		iface.Set(out)
+	default:
+		d.terror(n, mapTag, out)
+		return false
+	}
+
+	outt := out.Type()
+	kt := outt.Key()
+	et := outt.Elem()
+
+	stringMapType := d.stringMapType
+	generalMapType := d.generalMapType
+	if outt.Elem() == ifaceType {
+		if outt.Key().Kind() == reflect.String {
+			d.stringMapType = outt
+		} else if outt.Key() == ifaceType {
+			d.generalMapType = outt
+		}
+	}
+
+	mergedFields := d.mergedFields
+	d.mergedFields = nil
+
+	var mergeNode *Node
+
+	mapIsNew := false
+	if out.IsNil() {
+		out.Set(reflect.MakeMap(outt))
+		mapIsNew = true
+	}
+	for i := 0; i < l; i += 2 {
+		if isMerge(n.Content[i]) {
+			mergeNode = n.Content[i+1]
+			continue
+		}
+		k := reflect.New(kt).Elem()
+		if d.unmarshal(n.Content[i], k) {
+			if mergedFields != nil {
+				ki := k.Interface()
+				if mergedFields[ki] {
+					continue
+				}
+				mergedFields[ki] = true
+			}
+			kkind := k.Kind()
+			if kkind == reflect.Interface {
+				kkind = k.Elem().Kind()
+			}
+			if kkind == reflect.Map || kkind == reflect.Slice {
+				failf("invalid map key: %#v", k.Interface())
+			}
+			e := reflect.New(et).Elem()
+			if d.unmarshal(n.Content[i+1], e) || n.Content[i+1].ShortTag() == nullTag && (mapIsNew || !out.MapIndex(k).IsValid()) {
+				out.SetMapIndex(k, e)
+			}
+		}
+	}
+
+	d.mergedFields = mergedFields
+	if mergeNode != nil {
+		d.merge(n, mergeNode, out)
+	}
+
+	d.stringMapType = stringMapType
+	d.generalMapType = generalMapType
+	return true
+}
+
+func isStringMap(n *Node) bool {
+	if n.Kind != MappingNode {
+		return false
+	}
+	l := len(n.Content)
+	for i := 0; i < l; i += 2 {
+		shortTag := n.Content[i].ShortTag()
+		if shortTag != strTag && shortTag != mergeTag {
+			return false
+		}
+	}
+	return true
+}
+
+func (d *decoder) mappingStruct(n *Node, out reflect.Value) (good bool) {
+	sinfo, err := getStructInfo(out.Type())
+	if err != nil {
+		panic(err)
+	}
+
+	var inlineMap reflect.Value
+	var elemType reflect.Type
+	if sinfo.InlineMap != -1 {
+		inlineMap = out.Field(sinfo.InlineMap)
+		elemType = inlineMap.Type().Elem()
+	}
+
+	for _, index := range sinfo.InlineUnmarshalers {
+		field := d.fieldByIndex(n, out, index)
+		d.prepare(n, field)
+	}
+
+	mergedFields := d.mergedFields
+	d.mergedFields = nil
+	var mergeNode *Node
+	var doneFields []bool
+	if d.uniqueKeys {
+		doneFields = make([]bool, len(sinfo.FieldsList))
+	}
+	name := settableValueOf("")
+	l := len(n.Content)
+	for i := 0; i < l; i += 2 {
+		ni := n.Content[i]
+		if isMerge(ni) {
+			mergeNode = n.Content[i+1]
+			continue
+		}
+		if !d.unmarshal(ni, name) {
+			continue
+		}
+		sname := name.String()
+		if mergedFields != nil {
+			if mergedFields[sname] {
+				continue
+			}
+			mergedFields[sname] = true
+		}
+		if info, ok := sinfo.FieldsMap[sname]; ok {
+			if d.uniqueKeys {
+				if doneFields[info.Id] {
+					d.terrors = append(d.terrors, fmt.Sprintf("line %d: field %s already set in type %s", ni.Line, name.String(), out.Type()))
+					continue
+				}
+				doneFields[info.Id] = true
+			}
+			var field reflect.Value
+			if info.Inline == nil {
+				field = out.Field(info.Num)
+			} else {
+				field = d.fieldByIndex(n, out, info.Inline)
+			}
+			d.unmarshal(n.Content[i+1], field)
+		} else if sinfo.InlineMap != -1 {
+			if inlineMap.IsNil() {
+				inlineMap.Set(reflect.MakeMap(inlineMap.Type()))
+			}
+			value := reflect.New(elemType).Elem()
+			d.unmarshal(n.Content[i+1], value)
+			inlineMap.SetMapIndex(name, value)
+		} else if d.knownFields {
+			d.terrors = append(d.terrors, fmt.Sprintf("line %d: field %s not found in type %s", ni.Line, name.String(), out.Type()))
+		}
+	}
+
+	d.mergedFields = mergedFields
+	if mergeNode != nil {
+		d.merge(n, mergeNode, out)
+	}
+	return true
+}
+
+func failWantMap() {
+	failf("map merge requires map or sequence of maps as the value")
+}
+
+func (d *decoder) merge(parent *Node, merge *Node, out reflect.Value) {
+	mergedFields := d.mergedFields
+	if mergedFields == nil {
+		d.mergedFields = make(map[interface{}]bool)
+		for i := 0; i < len(parent.Content); i += 2 {
+			k := reflect.New(ifaceType).Elem()
+			if d.unmarshal(parent.Content[i], k) {
+				d.mergedFields[k.Interface()] = true
+			}
+		}
+	}
+
+	switch merge.Kind {
+	case MappingNode:
+		d.unmarshal(merge, out)
+	case AliasNode:
+		if merge.Alias != nil && merge.Alias.Kind != MappingNode {
+			failWantMap()
+		}
+		d.unmarshal(merge, out)
+	case SequenceNode:
+		for i := 0; i < len(merge.Content); i++ {
+			ni := merge.Content[i]
+			if ni.Kind == AliasNode {
+				if ni.Alias != nil && ni.Alias.Kind != MappingNode {
+					failWantMap()
+				}
+			} else if ni.Kind != MappingNode {
+				failWantMap()
+			}
+			d.unmarshal(ni, out)
+		}
+	default:
+		failWantMap()
+	}
+
+	d.mergedFields = mergedFields
+}
+
+func isMerge(n *Node) bool {
+	return n.Kind == ScalarNode && n.Value == "<<" && (n.Tag == "" || n.Tag == "!" || shortTag(n.Tag) == mergeTag)
+}
diff --git a/vendor/gopkg.in/yaml.v3/emitterc.go b/vendor/gopkg.in/yaml.v3/emitterc.go
new file mode 100644
index 000000000000..0f47c9ca8add
--- /dev/null
+++ b/vendor/gopkg.in/yaml.v3/emitterc.go
@@ -0,0 +1,2020 @@
+//
+// Copyright (c) 2011-2019 Canonical Ltd
+// Copyright (c) 2006-2010 Kirill Simonov
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy of
+// this software and associated documentation files (the "Software"), to deal in
+// the Software without restriction, including without limitation the rights to
+// use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+// of the Software, and to permit persons to whom the Software is furnished to do
+// so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+package yaml
+
+import (
+	"bytes"
+	"fmt"
+)
+
+// Flush the buffer if needed.
+func flush(emitter *yaml_emitter_t) bool {
+	if emitter.buffer_pos+5 >= len(emitter.buffer) {
+		return yaml_emitter_flush(emitter)
+	}
+	return true
+}
+
+// Put a character to the output buffer.
+func put(emitter *yaml_emitter_t, value byte) bool {
+	if emitter.buffer_pos+5 >= len(emitter.buffer) && !yaml_emitter_flush(emitter) {
+		return false
+	}
+	emitter.buffer[emitter.buffer_pos] = value
+	emitter.buffer_pos++
+	emitter.column++
+	return true
+}
+
+// Put a line break to the output buffer.
+func put_break(emitter *yaml_emitter_t) bool {
+	if emitter.buffer_pos+5 >= len(emitter.buffer) && !yaml_emitter_flush(emitter) {
+		return false
+	}
+	switch emitter.line_break {
+	case yaml_CR_BREAK:
+		emitter.buffer[emitter.buffer_pos] = '\r'
+		emitter.buffer_pos += 1
+	case yaml_LN_BREAK:
+		emitter.buffer[emitter.buffer_pos] = '\n'
+		emitter.buffer_pos += 1
+	case yaml_CRLN_BREAK:
+		emitter.buffer[emitter.buffer_pos+0] = '\r'
+		emitter.buffer[emitter.buffer_pos+1] = '\n'
+		emitter.buffer_pos += 2
+	default:
+		panic("unknown line break setting")
+	}
+	if emitter.column == 0 {
+		emitter.space_above = true
+	}
+	emitter.column = 0
+	emitter.line++
+	// [Go] Do this here and below and drop from everywhere else (see commented lines).
+	emitter.indention = true
+	return true
+}
+
+// Copy a character from a string into buffer.
+func write(emitter *yaml_emitter_t, s []byte, i *int) bool {
+	if emitter.buffer_pos+5 >= len(emitter.buffer) && !yaml_emitter_flush(emitter) {
+		return false
+	}
+	p := emitter.buffer_pos
+	w := width(s[*i])
+	switch w {
+	case 4:
+		emitter.buffer[p+3] = s[*i+3]
+		fallthrough
+	case 3:
+		emitter.buffer[p+2] = s[*i+2]
+		fallthrough
+	case 2:
+		emitter.buffer[p+1] = s[*i+1]
+		fallthrough
+	case 1:
+		emitter.buffer[p+0] = s[*i+0]
+	default:
+		panic("unknown character width")
+	}
+	emitter.column++
+	emitter.buffer_pos += w
+	*i += w
+	return true
+}
+
+// Write a whole string into buffer.
+func write_all(emitter *yaml_emitter_t, s []byte) bool {
+	for i := 0; i < len(s); {
+		if !write(emitter, s, &i) {
+			return false
+		}
+	}
+	return true
+}
+
+// Copy a line break character from a string into buffer.
+func write_break(emitter *yaml_emitter_t, s []byte, i *int) bool {
+	if s[*i] == '\n' {
+		if !put_break(emitter) {
+			return false
+		}
+		*i++
+	} else {
+		if !write(emitter, s, i) {
+			return false
+		}
+		if emitter.column == 0 {
+			emitter.space_above = true
+		}
+		emitter.column = 0
+		emitter.line++
+		// [Go] Do this here and above and drop from everywhere else (see commented lines).
+		emitter.indention = true
+	}
+	return true
+}
+
+// Set an emitter error and return false.
+func yaml_emitter_set_emitter_error(emitter *yaml_emitter_t, problem string) bool {
+	emitter.error = yaml_EMITTER_ERROR
+	emitter.problem = problem
+	return false
+}
+
+// Emit an event.
+func yaml_emitter_emit(emitter *yaml_emitter_t, event *yaml_event_t) bool {
+	emitter.events = append(emitter.events, *event)
+	for !yaml_emitter_need_more_events(emitter) {
+		event := &emitter.events[emitter.events_head]
+		if !yaml_emitter_analyze_event(emitter, event) {
+			return false
+		}
+		if !yaml_emitter_state_machine(emitter, event) {
+			return false
+		}
+		yaml_event_delete(event)
+		emitter.events_head++
+	}
+	return true
+}
+
+// Check if we need to accumulate more events before emitting.
+//
+// We accumulate extra
+//  - 1 event for DOCUMENT-START
+//  - 2 events for SEQUENCE-START
+//  - 3 events for MAPPING-START
+//
+func yaml_emitter_need_more_events(emitter *yaml_emitter_t) bool {
+	if emitter.events_head == len(emitter.events) {
+		return true
+	}
+	var accumulate int
+	switch emitter.events[emitter.events_head].typ {
+	case yaml_DOCUMENT_START_EVENT:
+		accumulate = 1
+		break
+	case yaml_SEQUENCE_START_EVENT:
+		accumulate = 2
+		break
+	case yaml_MAPPING_START_EVENT:
+		accumulate = 3
+		break
+	default:
+		return false
+	}
+	if len(emitter.events)-emitter.events_head > accumulate {
+		return false
+	}
+	var level int
+	for i := emitter.events_head; i < len(emitter.events); i++ {
+		switch emitter.events[i].typ {
+		case yaml_STREAM_START_EVENT, yaml_DOCUMENT_START_EVENT, yaml_SEQUENCE_START_EVENT, yaml_MAPPING_START_EVENT:
+			level++
+		case yaml_STREAM_END_EVENT, yaml_DOCUMENT_END_EVENT, yaml_SEQUENCE_END_EVENT, yaml_MAPPING_END_EVENT:
+			level--
+		}
+		if level == 0 {
+			return false
+		}
+	}
+	return true
+}
+
+// Append a directive to the directives stack.
+func yaml_emitter_append_tag_directive(emitter *yaml_emitter_t, value *yaml_tag_directive_t, allow_duplicates bool) bool {
+	for i := 0; i < len(emitter.tag_directives); i++ {
+		if bytes.Equal(value.handle, emitter.tag_directives[i].handle) {
+			if allow_duplicates {
+				return true
+			}
+			return yaml_emitter_set_emitter_error(emitter, "duplicate %TAG directive")
+		}
+	}
+
+	// [Go] Do we actually need to copy this given garbage collection
+	// and the lack of deallocating destructors?
+	tag_copy := yaml_tag_directive_t{
+		handle: make([]byte, len(value.handle)),
+		prefix: make([]byte, len(value.prefix)),
+	}
+	copy(tag_copy.handle, value.handle)
+	copy(tag_copy.prefix, value.prefix)
+	emitter.tag_directives = append(emitter.tag_directives, tag_copy)
+	return true
+}
+
+// Increase the indentation level.
+func yaml_emitter_increase_indent(emitter *yaml_emitter_t, flow, indentless bool) bool {
+	emitter.indents = append(emitter.indents, emitter.indent)
+	if emitter.indent < 0 {
+		if flow {
+			emitter.indent = emitter.best_indent
+		} else {
+			emitter.indent = 0
+		}
+	} else if !indentless {
+		// [Go] This was changed so that indentations are more regular.
+		if emitter.states[len(emitter.states)-1] == yaml_EMIT_BLOCK_SEQUENCE_ITEM_STATE {
+			// The first indent inside a sequence will just skip the "- " indicator.
+			emitter.indent += 2
+		} else {
+			// Everything else aligns to the chosen indentation.
+			emitter.indent = emitter.best_indent*((emitter.indent+emitter.best_indent)/emitter.best_indent)
+		}
+	}
+	return true
+}
+
+// State dispatcher.
+func yaml_emitter_state_machine(emitter *yaml_emitter_t, event *yaml_event_t) bool {
+	switch emitter.state {
+	default:
+	case yaml_EMIT_STREAM_START_STATE:
+		return yaml_emitter_emit_stream_start(emitter, event)
+
+	case yaml_EMIT_FIRST_DOCUMENT_START_STATE:
+		return yaml_emitter_emit_document_start(emitter, event, true)
+
+	case yaml_EMIT_DOCUMENT_START_STATE:
+		return yaml_emitter_emit_document_start(emitter, event, false)
+
+	case yaml_EMIT_DOCUMENT_CONTENT_STATE:
+		return yaml_emitter_emit_document_content(emitter, event)
+
+	case yaml_EMIT_DOCUMENT_END_STATE:
+		return yaml_emitter_emit_document_end(emitter, event)
+
+	case yaml_EMIT_FLOW_SEQUENCE_FIRST_ITEM_STATE:
+		return yaml_emitter_emit_flow_sequence_item(emitter, event, true, false)
+
+	case yaml_EMIT_FLOW_SEQUENCE_TRAIL_ITEM_STATE:
+		return yaml_emitter_emit_flow_sequence_item(emitter, event, false, true)
+
+	case yaml_EMIT_FLOW_SEQUENCE_ITEM_STATE:
+		return yaml_emitter_emit_flow_sequence_item(emitter, event, false, false)
+
+	case yaml_EMIT_FLOW_MAPPING_FIRST_KEY_STATE:
+		return yaml_emitter_emit_flow_mapping_key(emitter, event, true, false)
+
+	case yaml_EMIT_FLOW_MAPPING_TRAIL_KEY_STATE:
+		return yaml_emitter_emit_flow_mapping_key(emitter, event, false, true)
+
+	case yaml_EMIT_FLOW_MAPPING_KEY_STATE:
+		return yaml_emitter_emit_flow_mapping_key(emitter, event, false, false)
+
+	case yaml_EMIT_FLOW_MAPPING_SIMPLE_VALUE_STATE:
+		return yaml_emitter_emit_flow_mapping_value(emitter, event, true)
+
+	case yaml_EMIT_FLOW_MAPPING_VALUE_STATE:
+		return yaml_emitter_emit_flow_mapping_value(emitter, event, false)
+
+	case yaml_EMIT_BLOCK_SEQUENCE_FIRST_ITEM_STATE:
+		return yaml_emitter_emit_block_sequence_item(emitter, event, true)
+
+	case yaml_EMIT_BLOCK_SEQUENCE_ITEM_STATE:
+		return yaml_emitter_emit_block_sequence_item(emitter, event, false)
+
+	case yaml_EMIT_BLOCK_MAPPING_FIRST_KEY_STATE:
+		return yaml_emitter_emit_block_mapping_key(emitter, event, true)
+
+	case yaml_EMIT_BLOCK_MAPPING_KEY_STATE:
+		return yaml_emitter_emit_block_mapping_key(emitter, event, false)
+
+	case yaml_EMIT_BLOCK_MAPPING_SIMPLE_VALUE_STATE:
+		return yaml_emitter_emit_block_mapping_value(emitter, event, true)
+
+	case yaml_EMIT_BLOCK_MAPPING_VALUE_STATE:
+		return yaml_emitter_emit_block_mapping_value(emitter, event, false)
+
+	case yaml_EMIT_END_STATE:
+		return yaml_emitter_set_emitter_error(emitter, "expected nothing after STREAM-END")
+	}
+	panic("invalid emitter state")
+}
+
+// Expect STREAM-START.
+func yaml_emitter_emit_stream_start(emitter *yaml_emitter_t, event *yaml_event_t) bool {
+	if event.typ != yaml_STREAM_START_EVENT {
+		return yaml_emitter_set_emitter_error(emitter, "expected STREAM-START")
+	}
+	if emitter.encoding == yaml_ANY_ENCODING {
+		emitter.encoding = event.encoding
+		if emitter.encoding == yaml_ANY_ENCODING {
+			emitter.encoding = yaml_UTF8_ENCODING
+		}
+	}
+	if emitter.best_indent < 2 || emitter.best_indent > 9 {
+		emitter.best_indent = 2
+	}
+	if emitter.best_width >= 0 && emitter.best_width <= emitter.best_indent*2 {
+		emitter.best_width = 80
+	}
+	if emitter.best_width < 0 {
+		emitter.best_width = 1<<31 - 1
+	}
+	if emitter.line_break == yaml_ANY_BREAK {
+		emitter.line_break = yaml_LN_BREAK
+	}
+
+	emitter.indent = -1
+	emitter.line = 0
+	emitter.column = 0
+	emitter.whitespace = true
+	emitter.indention = true
+	emitter.space_above = true
+	emitter.foot_indent = -1
+
+	if emitter.encoding != yaml_UTF8_ENCODING {
+		if !yaml_emitter_write_bom(emitter) {
+			return false
+		}
+	}
+	emitter.state = yaml_EMIT_FIRST_DOCUMENT_START_STATE
+	return true
+}
+
+// Expect DOCUMENT-START or STREAM-END.
+func yaml_emitter_emit_document_start(emitter *yaml_emitter_t, event *yaml_event_t, first bool) bool {
+
+	if event.typ == yaml_DOCUMENT_START_EVENT {
+
+		if event.version_directive != nil {
+			if !yaml_emitter_analyze_version_directive(emitter, event.version_directive) {
+				return false
+			}
+		}
+
+		for i := 0; i < len(event.tag_directives); i++ {
+			tag_directive := &event.tag_directives[i]
+			if !yaml_emitter_analyze_tag_directive(emitter, tag_directive) {
+				return false
+			}
+			if !yaml_emitter_append_tag_directive(emitter, tag_directive, false) {
+				return false
+			}
+		}
+
+		for i := 0; i < len(default_tag_directives); i++ {
+			tag_directive := &default_tag_directives[i]
+			if !yaml_emitter_append_tag_directive(emitter, tag_directive, true) {
+				return false
+			}
+		}
+
+		implicit := event.implicit
+		if !first || emitter.canonical {
+			implicit = false
+		}
+
+		if emitter.open_ended && (event.version_directive != nil || len(event.tag_directives) > 0) {
+			if !yaml_emitter_write_indicator(emitter, []byte("..."), true, false, false) {
+				return false
+			}
+			if !yaml_emitter_write_indent(emitter) {
+				return false
+			}
+		}
+
+		if event.version_directive != nil {
+			implicit = false
+			if !yaml_emitter_write_indicator(emitter, []byte("%YAML"), true, false, false) {
+				return false
+			}
+			if !yaml_emitter_write_indicator(emitter, []byte("1.1"), true, false, false) {
+				return false
+			}
+			if !yaml_emitter_write_indent(emitter) {
+				return false
+			}
+		}
+
+		if len(event.tag_directives) > 0 {
+			implicit = false
+			for i := 0; i < len(event.tag_directives); i++ {
+				tag_directive := &event.tag_directives[i]
+				if !yaml_emitter_write_indicator(emitter, []byte("%TAG"), true, false, false) {
+					return false
+				}
+				if !yaml_emitter_write_tag_handle(emitter, tag_directive.handle) {
+					return false
+				}
+				if !yaml_emitter_write_tag_content(emitter, tag_directive.prefix, true) {
+					return false
+				}
+				if !yaml_emitter_write_indent(emitter) {
+					return false
+				}
+			}
+		}
+
+		if yaml_emitter_check_empty_document(emitter) {
+			implicit = false
+		}
+		if !implicit {
+			if !yaml_emitter_write_indent(emitter) {
+				return false
+			}
+			if !yaml_emitter_write_indicator(emitter, []byte("---"), true, false, false) {
+				return false
+			}
+			if emitter.canonical || true {
+				if !yaml_emitter_write_indent(emitter) {
+					return false
+				}
+			}
+		}
+
+		if len(emitter.head_comment) > 0 {
+			if !yaml_emitter_process_head_comment(emitter) {
+				return false
+			}
+			if !put_break(emitter) {
+				return false
+			}
+		}
+
+		emitter.state = yaml_EMIT_DOCUMENT_CONTENT_STATE
+		return true
+	}
+
+	if event.typ == yaml_STREAM_END_EVENT {
+		if emitter.open_ended {
+			if !yaml_emitter_write_indicator(emitter, []byte("..."), true, false, false) {
+				return false
+			}
+			if !yaml_emitter_write_indent(emitter) {
+				return false
+			}
+		}
+		if !yaml_emitter_flush(emitter) {
+			return false
+		}
+		emitter.state = yaml_EMIT_END_STATE
+		return true
+	}
+
+	return yaml_emitter_set_emitter_error(emitter, "expected DOCUMENT-START or STREAM-END")
+}
+
+// Expect the root node.
+func yaml_emitter_emit_document_content(emitter *yaml_emitter_t, event *yaml_event_t) bool {
+	emitter.states = append(emitter.states, yaml_EMIT_DOCUMENT_END_STATE)
+
+	if !yaml_emitter_process_head_comment(emitter) {
+		return false
+	}
+	if !yaml_emitter_emit_node(emitter, event, true, false, false, false) {
+		return false
+	}
+	if !yaml_emitter_process_line_comment(emitter) {
+		return false
+	}
+	if !yaml_emitter_process_foot_comment(emitter) {
+		return false
+	}
+	return true
+}
+
+// Expect DOCUMENT-END.
+func yaml_emitter_emit_document_end(emitter *yaml_emitter_t, event *yaml_event_t) bool {
+	if event.typ != yaml_DOCUMENT_END_EVENT {
+		return yaml_emitter_set_emitter_error(emitter, "expected DOCUMENT-END")
+	}
+	// [Go] Force document foot separation.
+	emitter.foot_indent = 0
+	if !yaml_emitter_process_foot_comment(emitter) {
+		return false
+	}
+	emitter.foot_indent = -1
+	if !yaml_emitter_write_indent(emitter) {
+		return false
+	}
+	if !event.implicit {
+		// [Go] Allocate the slice elsewhere.
+		if !yaml_emitter_write_indicator(emitter, []byte("..."), true, false, false) {
+			return false
+		}
+		if !yaml_emitter_write_indent(emitter) {
+			return false
+		}
+	}
+	if !yaml_emitter_flush(emitter) {
+		return false
+	}
+	emitter.state = yaml_EMIT_DOCUMENT_START_STATE
+	emitter.tag_directives = emitter.tag_directives[:0]
+	return true
+}
+
+// Expect a flow item node.
+func yaml_emitter_emit_flow_sequence_item(emitter *yaml_emitter_t, event *yaml_event_t, first, trail bool) bool {
+	if first {
+		if !yaml_emitter_write_indicator(emitter, []byte{'['}, true, true, false) {
+			return false
+		}
+		if !yaml_emitter_increase_indent(emitter, true, false) {
+			return false
+		}
+		emitter.flow_level++
+	}
+
+	if event.typ == yaml_SEQUENCE_END_EVENT {
+		if emitter.canonical && !first && !trail {
+			if !yaml_emitter_write_indicator(emitter, []byte{','}, false, false, false) {
+				return false
+			}
+		}
+		emitter.flow_level--
+		emitter.indent = emitter.indents[len(emitter.indents)-1]
+		emitter.indents = emitter.indents[:len(emitter.indents)-1]
+		if emitter.column == 0 || emitter.canonical && !first {
+			if !yaml_emitter_write_indent(emitter) {
+				return false
+			}
+		}
+		if !yaml_emitter_write_indicator(emitter, []byte{']'}, false, false, false) {
+			return false
+		}
+		if !yaml_emitter_process_line_comment(emitter) {
+			return false
+		}
+		if !yaml_emitter_process_foot_comment(emitter) {
+			return false
+		}
+		emitter.state = emitter.states[len(emitter.states)-1]
+		emitter.states = emitter.states[:len(emitter.states)-1]
+
+		return true
+	}
+
+	if !first && !trail {
+		if !yaml_emitter_write_indicator(emitter, []byte{','}, false, false, false) {
+			return false
+		}
+	}
+
+	if !yaml_emitter_process_head_comment(emitter) {
+		return false
+	}
+	if emitter.column == 0 {
+		if !yaml_emitter_write_indent(emitter) {
+			return false
+		}
+	}
+
+	if emitter.canonical || emitter.column > emitter.best_width {
+		if !yaml_emitter_write_indent(emitter) {
+			return false
+		}
+	}
+	if len(emitter.line_comment)+len(emitter.foot_comment)+len(emitter.tail_comment) > 0 {
+		emitter.states = append(emitter.states, yaml_EMIT_FLOW_SEQUENCE_TRAIL_ITEM_STATE)
+	} else {
+		emitter.states = append(emitter.states, yaml_EMIT_FLOW_SEQUENCE_ITEM_STATE)
+	}
+	if !yaml_emitter_emit_node(emitter, event, false, true, false, false) {
+		return false
+	}
+	if len(emitter.line_comment)+len(emitter.foot_comment)+len(emitter.tail_comment) > 0 {
+		if !yaml_emitter_write_indicator(emitter, []byte{','}, false, false, false) {
+			return false
+		}
+	}
+	if !yaml_emitter_process_line_comment(emitter) {
+		return false
+	}
+	if !yaml_emitter_process_foot_comment(emitter) {
+		return false
+	}
+	return true
+}
+
+// Expect a flow key node.
+func yaml_emitter_emit_flow_mapping_key(emitter *yaml_emitter_t, event *yaml_event_t, first, trail bool) bool {
+	if first {
+		if !yaml_emitter_write_indicator(emitter, []byte{'{'}, true, true, false) {
+			return false
+		}
+		if !yaml_emitter_increase_indent(emitter, true, false) {
+			return false
+		}
+		emitter.flow_level++
+	}
+
+	if event.typ == yaml_MAPPING_END_EVENT {
+		if (emitter.canonical || len(emitter.head_comment)+len(emitter.foot_comment)+len(emitter.tail_comment) > 0) && !first && !trail {
+			if !yaml_emitter_write_indicator(emitter, []byte{','}, false, false, false) {
+				return false
+			}
+		}
+		if !yaml_emitter_process_head_comment(emitter) {
+			return false
+		}
+		emitter.flow_level--
+		emitter.indent = emitter.indents[len(emitter.indents)-1]
+		emitter.indents = emitter.indents[:len(emitter.indents)-1]
+		if emitter.canonical && !first {
+			if !yaml_emitter_write_indent(emitter) {
+				return false
+			}
+		}
+		if !yaml_emitter_write_indicator(emitter, []byte{'}'}, false, false, false) {
+			return false
+		}
+		if !yaml_emitter_process_line_comment(emitter) {
+			return false
+		}
+		if !yaml_emitter_process_foot_comment(emitter) {
+			return false
+		}
+		emitter.state = emitter.states[len(emitter.states)-1]
+		emitter.states = emitter.states[:len(emitter.states)-1]
+		return true
+	}
+
+	if !first && !trail {
+		if !yaml_emitter_write_indicator(emitter, []byte{','}, false, false, false) {
+			return false
+		}
+	}
+
+	if !yaml_emitter_process_head_comment(emitter) {
+		return false
+	}
+
+	if emitter.column == 0 {
+		if !yaml_emitter_write_indent(emitter) {
+			return false
+		}
+	}
+
+	if emitter.canonical || emitter.column > emitter.best_width {
+		if !yaml_emitter_write_indent(emitter) {
+			return false
+		}
+	}
+
+	if !emitter.canonical && yaml_emitter_check_simple_key(emitter) {
+		emitter.states = append(emitter.states, yaml_EMIT_FLOW_MAPPING_SIMPLE_VALUE_STATE)
+		return yaml_emitter_emit_node(emitter, event, false, false, true, true)
+	}
+	if !yaml_emitter_write_indicator(emitter, []byte{'?'}, true, false, false) {
+		return false
+	}
+	emitter.states = append(emitter.states, yaml_EMIT_FLOW_MAPPING_VALUE_STATE)
+	return yaml_emitter_emit_node(emitter, event, false, false, true, false)
+}
+
+// Expect a flow value node.
+func yaml_emitter_emit_flow_mapping_value(emitter *yaml_emitter_t, event *yaml_event_t, simple bool) bool {
+	if simple {
+		if !yaml_emitter_write_indicator(emitter, []byte{':'}, false, false, false) {
+			return false
+		}
+	} else {
+		if emitter.canonical || emitter.column > emitter.best_width {
+			if !yaml_emitter_write_indent(emitter) {
+				return false
+			}
+		}
+		if !yaml_emitter_write_indicator(emitter, []byte{':'}, true, false, false) {
+			return false
+		}
+	}
+	if len(emitter.line_comment)+len(emitter.foot_comment)+len(emitter.tail_comment) > 0 {
+		emitter.states = append(emitter.states, yaml_EMIT_FLOW_MAPPING_TRAIL_KEY_STATE)
+	} else {
+		emitter.states = append(emitter.states, yaml_EMIT_FLOW_MAPPING_KEY_STATE)
+	}
+	if !yaml_emitter_emit_node(emitter, event, false, false, true, false) {
+		return false
+	}
+	if len(emitter.line_comment)+len(emitter.foot_comment)+len(emitter.tail_comment) > 0 {
+		if !yaml_emitter_write_indicator(emitter, []byte{','}, false, false, false) {
+			return false
+		}
+	}
+	if !yaml_emitter_process_line_comment(emitter) {
+		return false
+	}
+	if !yaml_emitter_process_foot_comment(emitter) {
+		return false
+	}
+	return true
+}
+
+// Expect a block item node.
+func yaml_emitter_emit_block_sequence_item(emitter *yaml_emitter_t, event *yaml_event_t, first bool) bool {
+	if first {
+		if !yaml_emitter_increase_indent(emitter, false, false) {
+			return false
+		}
+	}
+	if event.typ == yaml_SEQUENCE_END_EVENT {
+		emitter.indent = emitter.indents[len(emitter.indents)-1]
+		emitter.indents = emitter.indents[:len(emitter.indents)-1]
+		emitter.state = emitter.states[len(emitter.states)-1]
+		emitter.states = emitter.states[:len(emitter.states)-1]
+		return true
+	}
+	if !yaml_emitter_process_head_comment(emitter) {
+		return false
+	}
+	if !yaml_emitter_write_indent(emitter) {
+		return false
+	}
+	if !yaml_emitter_write_indicator(emitter, []byte{'-'}, true, false, true) {
+		return false
+	}
+	emitter.states = append(emitter.states, yaml_EMIT_BLOCK_SEQUENCE_ITEM_STATE)
+	if !yaml_emitter_emit_node(emitter, event, false, true, false, false) {
+		return false
+	}
+	if !yaml_emitter_process_line_comment(emitter) {
+		return false
+	}
+	if !yaml_emitter_process_foot_comment(emitter) {
+		return false
+	}
+	return true
+}
+
+// Expect a block key node.
+func yaml_emitter_emit_block_mapping_key(emitter *yaml_emitter_t, event *yaml_event_t, first bool) bool {
+	if first {
+		if !yaml_emitter_increase_indent(emitter, false, false) {
+			return false
+		}
+	}
+	if !yaml_emitter_process_head_comment(emitter) {
+		return false
+	}
+	if event.typ == yaml_MAPPING_END_EVENT {
+		emitter.indent = emitter.indents[len(emitter.indents)-1]
+		emitter.indents = emitter.indents[:len(emitter.indents)-1]
+		emitter.state = emitter.states[len(emitter.states)-1]
+		emitter.states = emitter.states[:len(emitter.states)-1]
+		return true
+	}
+	if !yaml_emitter_write_indent(emitter) {
+		return false
+	}
+	if len(emitter.line_comment) > 0 {
+		// [Go] A line comment was provided for the key. That's unusual as the
+		//      scanner associates line comments with the value. Either way,
+		//      save the line comment and render it appropriately later.
+		emitter.key_line_comment = emitter.line_comment
+		emitter.line_comment = nil
+	}
+	if yaml_emitter_check_simple_key(emitter) {
+		emitter.states = append(emitter.states, yaml_EMIT_BLOCK_MAPPING_SIMPLE_VALUE_STATE)
+		return yaml_emitter_emit_node(emitter, event, false, false, true, true)
+	}
+	if !yaml_emitter_write_indicator(emitter, []byte{'?'}, true, false, true) {
+		return false
+	}
+	emitter.states = append(emitter.states, yaml_EMIT_BLOCK_MAPPING_VALUE_STATE)
+	return yaml_emitter_emit_node(emitter, event, false, false, true, false)
+}
+
+// Expect a block value node.
+func yaml_emitter_emit_block_mapping_value(emitter *yaml_emitter_t, event *yaml_event_t, simple bool) bool {
+	if simple {
+		if !yaml_emitter_write_indicator(emitter, []byte{':'}, false, false, false) {
+			return false
+		}
+	} else {
+		if !yaml_emitter_write_indent(emitter) {
+			return false
+		}
+		if !yaml_emitter_write_indicator(emitter, []byte{':'}, true, false, true) {
+			return false
+		}
+	}
+	if len(emitter.key_line_comment) > 0 {
+		// [Go] Line comments are generally associated with the value, but when there's
+		//      no value on the same line as a mapping key they end up attached to the
+		//      key itself.
+		if event.typ == yaml_SCALAR_EVENT {
+			if len(emitter.line_comment) == 0 {
+				// A scalar is coming and it has no line comments by itself yet,
+				// so just let it handle the line comment as usual. If it has a
+				// line comment, we can't have both so the one from the key is lost.
+				emitter.line_comment = emitter.key_line_comment
+				emitter.key_line_comment = nil
+			}
+		} else if event.sequence_style() != yaml_FLOW_SEQUENCE_STYLE && (event.typ == yaml_MAPPING_START_EVENT || event.typ == yaml_SEQUENCE_START_EVENT) {
+			// An indented block follows, so write the comment right now.
+			emitter.line_comment, emitter.key_line_comment = emitter.key_line_comment, emitter.line_comment
+			if !yaml_emitter_process_line_comment(emitter) {
+				return false
+			}
+			emitter.line_comment, emitter.key_line_comment = emitter.key_line_comment, emitter.line_comment
+		}
+	}
+	emitter.states = append(emitter.states, yaml_EMIT_BLOCK_MAPPING_KEY_STATE)
+	if !yaml_emitter_emit_node(emitter, event, false, false, true, false) {
+		return false
+	}
+	if !yaml_emitter_process_line_comment(emitter) {
+		return false
+	}
+	if !yaml_emitter_process_foot_comment(emitter) {
+		return false
+	}
+	return true
+}
+
+func yaml_emitter_silent_nil_event(emitter *yaml_emitter_t, event *yaml_event_t) bool {
+	return event.typ == yaml_SCALAR_EVENT && event.implicit && !emitter.canonical && len(emitter.scalar_data.value) == 0
+}
+
+// Expect a node.
+func yaml_emitter_emit_node(emitter *yaml_emitter_t, event *yaml_event_t,
+	root bool, sequence bool, mapping bool, simple_key bool) bool {
+
+	emitter.root_context = root
+	emitter.sequence_context = sequence
+	emitter.mapping_context = mapping
+	emitter.simple_key_context = simple_key
+
+	switch event.typ {
+	case yaml_ALIAS_EVENT:
+		return yaml_emitter_emit_alias(emitter, event)
+	case yaml_SCALAR_EVENT:
+		return yaml_emitter_emit_scalar(emitter, event)
+	case yaml_SEQUENCE_START_EVENT:
+		return yaml_emitter_emit_sequence_start(emitter, event)
+	case yaml_MAPPING_START_EVENT:
+		return yaml_emitter_emit_mapping_start(emitter, event)
+	default:
+		return yaml_emitter_set_emitter_error(emitter,
+			fmt.Sprintf("expected SCALAR, SEQUENCE-START, MAPPING-START, or ALIAS, but got %v", event.typ))
+	}
+}
+
+// Expect ALIAS.
+func yaml_emitter_emit_alias(emitter *yaml_emitter_t, event *yaml_event_t) bool {
+	if !yaml_emitter_process_anchor(emitter) {
+		return false
+	}
+	emitter.state = emitter.states[len(emitter.states)-1]
+	emitter.states = emitter.states[:len(emitter.states)-1]
+	return true
+}
+
+// Expect SCALAR.
+func yaml_emitter_emit_scalar(emitter *yaml_emitter_t, event *yaml_event_t) bool {
+	if !yaml_emitter_select_scalar_style(emitter, event) {
+		return false
+	}
+	if !yaml_emitter_process_anchor(emitter) {
+		return false
+	}
+	if !yaml_emitter_process_tag(emitter) {
+		return false
+	}
+	if !yaml_emitter_increase_indent(emitter, true, false) {
+		return false
+	}
+	if !yaml_emitter_process_scalar(emitter) {
+		return false
+	}
+	emitter.indent = emitter.indents[len(emitter.indents)-1]
+	emitter.indents = emitter.indents[:len(emitter.indents)-1]
+	emitter.state = emitter.states[len(emitter.states)-1]
+	emitter.states = emitter.states[:len(emitter.states)-1]
+	return true
+}
+
+// Expect SEQUENCE-START.
+func yaml_emitter_emit_sequence_start(emitter *yaml_emitter_t, event *yaml_event_t) bool {
+	if !yaml_emitter_process_anchor(emitter) {
+		return false
+	}
+	if !yaml_emitter_process_tag(emitter) {
+		return false
+	}
+	if emitter.flow_level > 0 || emitter.canonical || event.sequence_style() == yaml_FLOW_SEQUENCE_STYLE ||
+		yaml_emitter_check_empty_sequence(emitter) {
+		emitter.state = yaml_EMIT_FLOW_SEQUENCE_FIRST_ITEM_STATE
+	} else {
+		emitter.state = yaml_EMIT_BLOCK_SEQUENCE_FIRST_ITEM_STATE
+	}
+	return true
+}
+
+// Expect MAPPING-START.
+func yaml_emitter_emit_mapping_start(emitter *yaml_emitter_t, event *yaml_event_t) bool {
+	if !yaml_emitter_process_anchor(emitter) {
+		return false
+	}
+	if !yaml_emitter_process_tag(emitter) {
+		return false
+	}
+	if emitter.flow_level > 0 || emitter.canonical || event.mapping_style() == yaml_FLOW_MAPPING_STYLE ||
+		yaml_emitter_check_empty_mapping(emitter) {
+		emitter.state = yaml_EMIT_FLOW_MAPPING_FIRST_KEY_STATE
+	} else {
+		emitter.state = yaml_EMIT_BLOCK_MAPPING_FIRST_KEY_STATE
+	}
+	return true
+}
+
+// Check if the document content is an empty scalar.
+func yaml_emitter_check_empty_document(emitter *yaml_emitter_t) bool {
+	return false // [Go] Huh?
+}
+
+// Check if the next events represent an empty sequence.
+func yaml_emitter_check_empty_sequence(emitter *yaml_emitter_t) bool {
+	if len(emitter.events)-emitter.events_head < 2 {
+		return false
+	}
+	return emitter.events[emitter.events_head].typ == yaml_SEQUENCE_START_EVENT &&
+		emitter.events[emitter.events_head+1].typ == yaml_SEQUENCE_END_EVENT
+}
+
+// Check if the next events represent an empty mapping.
+func yaml_emitter_check_empty_mapping(emitter *yaml_emitter_t) bool {
+	if len(emitter.events)-emitter.events_head < 2 {
+		return false
+	}
+	return emitter.events[emitter.events_head].typ == yaml_MAPPING_START_EVENT &&
+		emitter.events[emitter.events_head+1].typ == yaml_MAPPING_END_EVENT
+}
+
+// Check if the next node can be expressed as a simple key.
+func yaml_emitter_check_simple_key(emitter *yaml_emitter_t) bool {
+	length := 0
+	switch emitter.events[emitter.events_head].typ {
+	case yaml_ALIAS_EVENT:
+		length += len(emitter.anchor_data.anchor)
+	case yaml_SCALAR_EVENT:
+		if emitter.scalar_data.multiline {
+			return false
+		}
+		length += len(emitter.anchor_data.anchor) +
+			len(emitter.tag_data.handle) +
+			len(emitter.tag_data.suffix) +
+			len(emitter.scalar_data.value)
+	case yaml_SEQUENCE_START_EVENT:
+		if !yaml_emitter_check_empty_sequence(emitter) {
+			return false
+		}
+		length += len(emitter.anchor_data.anchor) +
+			len(emitter.tag_data.handle) +
+			len(emitter.tag_data.suffix)
+	case yaml_MAPPING_START_EVENT:
+		if !yaml_emitter_check_empty_mapping(emitter) {
+			return false
+		}
+		length += len(emitter.anchor_data.anchor) +
+			len(emitter.tag_data.handle) +
+			len(emitter.tag_data.suffix)
+	default:
+		return false
+	}
+	return length <= 128
+}
+
+// Determine an acceptable scalar style.
+func yaml_emitter_select_scalar_style(emitter *yaml_emitter_t, event *yaml_event_t) bool {
+
+	no_tag := len(emitter.tag_data.handle) == 0 && len(emitter.tag_data.suffix) == 0
+	if no_tag && !event.implicit && !event.quoted_implicit {
+		return yaml_emitter_set_emitter_error(emitter, "neither tag nor implicit flags are specified")
+	}
+
+	style := event.scalar_style()
+	if style == yaml_ANY_SCALAR_STYLE {
+		style = yaml_PLAIN_SCALAR_STYLE
+	}
+	if emitter.canonical {
+		style = yaml_DOUBLE_QUOTED_SCALAR_STYLE
+	}
+	if emitter.simple_key_context && emitter.scalar_data.multiline {
+		style = yaml_DOUBLE_QUOTED_SCALAR_STYLE
+	}
+
+	if style == yaml_PLAIN_SCALAR_STYLE {
+		if emitter.flow_level > 0 && !emitter.scalar_data.flow_plain_allowed ||
+			emitter.flow_level == 0 && !emitter.scalar_data.block_plain_allowed {
+			style = yaml_SINGLE_QUOTED_SCALAR_STYLE
+		}
+		if len(emitter.scalar_data.value) == 0 && (emitter.flow_level > 0 || emitter.simple_key_context) {
+			style = yaml_SINGLE_QUOTED_SCALAR_STYLE
+		}
+		if no_tag && !event.implicit {
+			style = yaml_SINGLE_QUOTED_SCALAR_STYLE
+		}
+	}
+	if style == yaml_SINGLE_QUOTED_SCALAR_STYLE {
+		if !emitter.scalar_data.single_quoted_allowed {
+			style = yaml_DOUBLE_QUOTED_SCALAR_STYLE
+		}
+	}
+	if style == yaml_LITERAL_SCALAR_STYLE || style == yaml_FOLDED_SCALAR_STYLE {
+		if !emitter.scalar_data.block_allowed || emitter.flow_level > 0 || emitter.simple_key_context {
+			style = yaml_DOUBLE_QUOTED_SCALAR_STYLE
+		}
+	}
+
+	if no_tag && !event.quoted_implicit && style != yaml_PLAIN_SCALAR_STYLE {
+		emitter.tag_data.handle = []byte{'!'}
+	}
+	emitter.scalar_data.style = style
+	return true
+}
+
+// Write an anchor.
+func yaml_emitter_process_anchor(emitter *yaml_emitter_t) bool {
+	if emitter.anchor_data.anchor == nil {
+		return true
+	}
+	c := []byte{'&'}
+	if emitter.anchor_data.alias {
+		c[0] = '*'
+	}
+	if !yaml_emitter_write_indicator(emitter, c, true, false, false) {
+		return false
+	}
+	return yaml_emitter_write_anchor(emitter, emitter.anchor_data.anchor)
+}
+
+// Write a tag.
+func yaml_emitter_process_tag(emitter *yaml_emitter_t) bool {
+	if len(emitter.tag_data.handle) == 0 && len(emitter.tag_data.suffix) == 0 {
+		return true
+	}
+	if len(emitter.tag_data.handle) > 0 {
+		if !yaml_emitter_write_tag_handle(emitter, emitter.tag_data.handle) {
+			return false
+		}
+		if len(emitter.tag_data.suffix) > 0 {
+			if !yaml_emitter_write_tag_content(emitter, emitter.tag_data.suffix, false) {
+				return false
+			}
+		}
+	} else {
+		// [Go] Allocate these slices elsewhere.
+		if !yaml_emitter_write_indicator(emitter, []byte("!<"), true, false, false) {
+			return false
+		}
+		if !yaml_emitter_write_tag_content(emitter, emitter.tag_data.suffix, false) {
+			return false
+		}
+		if !yaml_emitter_write_indicator(emitter, []byte{'>'}, false, false, false) {
+			return false
+		}
+	}
+	return true
+}
+
+// Write a scalar.
+func yaml_emitter_process_scalar(emitter *yaml_emitter_t) bool {
+	switch emitter.scalar_data.style {
+	case yaml_PLAIN_SCALAR_STYLE:
+		return yaml_emitter_write_plain_scalar(emitter, emitter.scalar_data.value, !emitter.simple_key_context)
+
+	case yaml_SINGLE_QUOTED_SCALAR_STYLE:
+		return yaml_emitter_write_single_quoted_scalar(emitter, emitter.scalar_data.value, !emitter.simple_key_context)
+
+	case yaml_DOUBLE_QUOTED_SCALAR_STYLE:
+		return yaml_emitter_write_double_quoted_scalar(emitter, emitter.scalar_data.value, !emitter.simple_key_context)
+
+	case yaml_LITERAL_SCALAR_STYLE:
+		return yaml_emitter_write_literal_scalar(emitter, emitter.scalar_data.value)
+
+	case yaml_FOLDED_SCALAR_STYLE:
+		return yaml_emitter_write_folded_scalar(emitter, emitter.scalar_data.value)
+	}
+	panic("unknown scalar style")
+}
+
+// Write a head comment.
+func yaml_emitter_process_head_comment(emitter *yaml_emitter_t) bool {
+	if len(emitter.tail_comment) > 0 {
+		if !yaml_emitter_write_indent(emitter) {
+			return false
+		}
+		if !yaml_emitter_write_comment(emitter, emitter.tail_comment) {
+			return false
+		}
+		emitter.tail_comment = emitter.tail_comment[:0]
+		emitter.foot_indent = emitter.indent
+		if emitter.foot_indent < 0 {
+			emitter.foot_indent = 0
+		}
+	}
+
+	if len(emitter.head_comment) == 0 {
+		return true
+	}
+	if !yaml_emitter_write_indent(emitter) {
+		return false
+	}
+	if !yaml_emitter_write_comment(emitter, emitter.head_comment) {
+		return false
+	}
+	emitter.head_comment = emitter.head_comment[:0]
+	return true
+}
+
+// Write an line comment.
+func yaml_emitter_process_line_comment(emitter *yaml_emitter_t) bool {
+	if len(emitter.line_comment) == 0 {
+		return true
+	}
+	if !emitter.whitespace {
+		if !put(emitter, ' ') {
+			return false
+		}
+	}
+	if !yaml_emitter_write_comment(emitter, emitter.line_comment) {
+		return false
+	}
+	emitter.line_comment = emitter.line_comment[:0]
+	return true
+}
+
+// Write a foot comment.
+func yaml_emitter_process_foot_comment(emitter *yaml_emitter_t) bool {
+	if len(emitter.foot_comment) == 0 {
+		return true
+	}
+	if !yaml_emitter_write_indent(emitter) {
+		return false
+	}
+	if !yaml_emitter_write_comment(emitter, emitter.foot_comment) {
+		return false
+	}
+	emitter.foot_comment = emitter.foot_comment[:0]
+	emitter.foot_indent = emitter.indent
+	if emitter.foot_indent < 0 {
+		emitter.foot_indent = 0
+	}
+	return true
+}
+
+// Check if a %YAML directive is valid.
+func yaml_emitter_analyze_version_directive(emitter *yaml_emitter_t, version_directive *yaml_version_directive_t) bool {
+	if version_directive.major != 1 || version_directive.minor != 1 {
+		return yaml_emitter_set_emitter_error(emitter, "incompatible %YAML directive")
+	}
+	return true
+}
+
+// Check if a %TAG directive is valid.
+func yaml_emitter_analyze_tag_directive(emitter *yaml_emitter_t, tag_directive *yaml_tag_directive_t) bool {
+	handle := tag_directive.handle
+	prefix := tag_directive.prefix
+	if len(handle) == 0 {
+		return yaml_emitter_set_emitter_error(emitter, "tag handle must not be empty")
+	}
+	if handle[0] != '!' {
+		return yaml_emitter_set_emitter_error(emitter, "tag handle must start with '!'")
+	}
+	if handle[len(handle)-1] != '!' {
+		return yaml_emitter_set_emitter_error(emitter, "tag handle must end with '!'")
+	}
+	for i := 1; i < len(handle)-1; i += width(handle[i]) {
+		if !is_alpha(handle, i) {
+			return yaml_emitter_set_emitter_error(emitter, "tag handle must contain alphanumerical characters only")
+		}
+	}
+	if len(prefix) == 0 {
+		return yaml_emitter_set_emitter_error(emitter, "tag prefix must not be empty")
+	}
+	return true
+}
+
+// Check if an anchor is valid.
+func yaml_emitter_analyze_anchor(emitter *yaml_emitter_t, anchor []byte, alias bool) bool {
+	if len(anchor) == 0 {
+		problem := "anchor value must not be empty"
+		if alias {
+			problem = "alias value must not be empty"
+		}
+		return yaml_emitter_set_emitter_error(emitter, problem)
+	}
+	for i := 0; i < len(anchor); i += width(anchor[i]) {
+		if !is_alpha(anchor, i) {
+			problem := "anchor value must contain alphanumerical characters only"
+			if alias {
+				problem = "alias value must contain alphanumerical characters only"
+			}
+			return yaml_emitter_set_emitter_error(emitter, problem)
+		}
+	}
+	emitter.anchor_data.anchor = anchor
+	emitter.anchor_data.alias = alias
+	return true
+}
+
+// Check if a tag is valid.
+func yaml_emitter_analyze_tag(emitter *yaml_emitter_t, tag []byte) bool {
+	if len(tag) == 0 {
+		return yaml_emitter_set_emitter_error(emitter, "tag value must not be empty")
+	}
+	for i := 0; i < len(emitter.tag_directives); i++ {
+		tag_directive := &emitter.tag_directives[i]
+		if bytes.HasPrefix(tag, tag_directive.prefix) {
+			emitter.tag_data.handle = tag_directive.handle
+			emitter.tag_data.suffix = tag[len(tag_directive.prefix):]
+			return true
+		}
+	}
+	emitter.tag_data.suffix = tag
+	return true
+}
+
+// Check if a scalar is valid.
+func yaml_emitter_analyze_scalar(emitter *yaml_emitter_t, value []byte) bool {
+	var (
+		block_indicators   = false
+		flow_indicators    = false
+		line_breaks        = false
+		special_characters = false
+		tab_characters     = false
+
+		leading_space  = false
+		leading_break  = false
+		trailing_space = false
+		trailing_break = false
+		break_space    = false
+		space_break    = false
+
+		preceded_by_whitespace = false
+		followed_by_whitespace = false
+		previous_space         = false
+		previous_break         = false
+	)
+
+	emitter.scalar_data.value = value
+
+	if len(value) == 0 {
+		emitter.scalar_data.multiline = false
+		emitter.scalar_data.flow_plain_allowed = false
+		emitter.scalar_data.block_plain_allowed = true
+		emitter.scalar_data.single_quoted_allowed = true
+		emitter.scalar_data.block_allowed = false
+		return true
+	}
+
+	if len(value) >= 3 && ((value[0] == '-' && value[1] == '-' && value[2] == '-') || (value[0] == '.' && value[1] == '.' && value[2] == '.')) {
+		block_indicators = true
+		flow_indicators = true
+	}
+
+	preceded_by_whitespace = true
+	for i, w := 0, 0; i < len(value); i += w {
+		w = width(value[i])
+		followed_by_whitespace = i+w >= len(value) || is_blank(value, i+w)
+
+		if i == 0 {
+			switch value[i] {
+			case '#', ',', '[', ']', '{', '}', '&', '*', '!', '|', '>', '\'', '"', '%', '@', '`':
+				flow_indicators = true
+				block_indicators = true
+			case '?', ':':
+				flow_indicators = true
+				if followed_by_whitespace {
+					block_indicators = true
+				}
+			case '-':
+				if followed_by_whitespace {
+					flow_indicators = true
+					block_indicators = true
+				}
+			}
+		} else {
+			switch value[i] {
+			case ',', '?', '[', ']', '{', '}':
+				flow_indicators = true
+			case ':':
+				flow_indicators = true
+				if followed_by_whitespace {
+					block_indicators = true
+				}
+			case '#':
+				if preceded_by_whitespace {
+					flow_indicators = true
+					block_indicators = true
+				}
+			}
+		}
+
+		if value[i] == '\t' {
+			tab_characters = true
+		} else if !is_printable(value, i) || !is_ascii(value, i) && !emitter.unicode {
+			special_characters = true
+		}
+		if is_space(value, i) {
+			if i == 0 {
+				leading_space = true
+			}
+			if i+width(value[i]) == len(value) {
+				trailing_space = true
+			}
+			if previous_break {
+				break_space = true
+			}
+			previous_space = true
+			previous_break = false
+		} else if is_break(value, i) {
+			line_breaks = true
+			if i == 0 {
+				leading_break = true
+			}
+			if i+width(value[i]) == len(value) {
+				trailing_break = true
+			}
+			if previous_space {
+				space_break = true
+			}
+			previous_space = false
+			previous_break = true
+		} else {
+			previous_space = false
+			previous_break = false
+		}
+
+		// [Go]: Why 'z'? Couldn't be the end of the string as that's the loop condition.
+		preceded_by_whitespace = is_blankz(value, i)
+	}
+
+	emitter.scalar_data.multiline = line_breaks
+	emitter.scalar_data.flow_plain_allowed = true
+	emitter.scalar_data.block_plain_allowed = true
+	emitter.scalar_data.single_quoted_allowed = true
+	emitter.scalar_data.block_allowed = true
+
+	if leading_space || leading_break || trailing_space || trailing_break {
+		emitter.scalar_data.flow_plain_allowed = false
+		emitter.scalar_data.block_plain_allowed = false
+	}
+	if trailing_space {
+		emitter.scalar_data.block_allowed = false
+	}
+	if break_space {
+		emitter.scalar_data.flow_plain_allowed = false
+		emitter.scalar_data.block_plain_allowed = false
+		emitter.scalar_data.single_quoted_allowed = false
+	}
+	if space_break || tab_characters || special_characters {
+		emitter.scalar_data.flow_plain_allowed = false
+		emitter.scalar_data.block_plain_allowed = false
+		emitter.scalar_data.single_quoted_allowed = false
+	}
+	if space_break || special_characters {
+		emitter.scalar_data.block_allowed = false
+	}
+	if line_breaks {
+		emitter.scalar_data.flow_plain_allowed = false
+		emitter.scalar_data.block_plain_allowed = false
+	}
+	if flow_indicators {
+		emitter.scalar_data.flow_plain_allowed = false
+	}
+	if block_indicators {
+		emitter.scalar_data.block_plain_allowed = false
+	}
+	return true
+}
+
+// Check if the event data is valid.
+func yaml_emitter_analyze_event(emitter *yaml_emitter_t, event *yaml_event_t) bool {
+
+	emitter.anchor_data.anchor = nil
+	emitter.tag_data.handle = nil
+	emitter.tag_data.suffix = nil
+	emitter.scalar_data.value = nil
+
+	if len(event.head_comment) > 0 {
+		emitter.head_comment = event.head_comment
+	}
+	if len(event.line_comment) > 0 {
+		emitter.line_comment = event.line_comment
+	}
+	if len(event.foot_comment) > 0 {
+		emitter.foot_comment = event.foot_comment
+	}
+	if len(event.tail_comment) > 0 {
+		emitter.tail_comment = event.tail_comment
+	}
+
+	switch event.typ {
+	case yaml_ALIAS_EVENT:
+		if !yaml_emitter_analyze_anchor(emitter, event.anchor, true) {
+			return false
+		}
+
+	case yaml_SCALAR_EVENT:
+		if len(event.anchor) > 0 {
+			if !yaml_emitter_analyze_anchor(emitter, event.anchor, false) {
+				return false
+			}
+		}
+		if len(event.tag) > 0 && (emitter.canonical || (!event.implicit && !event.quoted_implicit)) {
+			if !yaml_emitter_analyze_tag(emitter, event.tag) {
+				return false
+			}
+		}
+		if !yaml_emitter_analyze_scalar(emitter, event.value) {
+			return false
+		}
+
+	case yaml_SEQUENCE_START_EVENT:
+		if len(event.anchor) > 0 {
+			if !yaml_emitter_analyze_anchor(emitter, event.anchor, false) {
+				return false
+			}
+		}
+		if len(event.tag) > 0 && (emitter.canonical || !event.implicit) {
+			if !yaml_emitter_analyze_tag(emitter, event.tag) {
+				return false
+			}
+		}
+
+	case yaml_MAPPING_START_EVENT:
+		if len(event.anchor) > 0 {
+			if !yaml_emitter_analyze_anchor(emitter, event.anchor, false) {
+				return false
+			}
+		}
+		if len(event.tag) > 0 && (emitter.canonical || !event.implicit) {
+			if !yaml_emitter_analyze_tag(emitter, event.tag) {
+				return false
+			}
+		}
+	}
+	return true
+}
+
+// Write the BOM character.
+func yaml_emitter_write_bom(emitter *yaml_emitter_t) bool {
+	if !flush(emitter) {
+		return false
+	}
+	pos := emitter.buffer_pos
+	emitter.buffer[pos+0] = '\xEF'
+	emitter.buffer[pos+1] = '\xBB'
+	emitter.buffer[pos+2] = '\xBF'
+	emitter.buffer_pos += 3
+	return true
+}
+
+func yaml_emitter_write_indent(emitter *yaml_emitter_t) bool {
+	indent := emitter.indent
+	if indent < 0 {
+		indent = 0
+	}
+	if !emitter.indention || emitter.column > indent || (emitter.column == indent && !emitter.whitespace) {
+		if !put_break(emitter) {
+			return false
+		}
+	}
+	if emitter.foot_indent == indent {
+		if !put_break(emitter) {
+			return false
+		}
+	}
+	for emitter.column < indent {
+		if !put(emitter, ' ') {
+			return false
+		}
+	}
+	emitter.whitespace = true
+	//emitter.indention = true
+	emitter.space_above = false
+	emitter.foot_indent = -1
+	return true
+}
+
+func yaml_emitter_write_indicator(emitter *yaml_emitter_t, indicator []byte, need_whitespace, is_whitespace, is_indention bool) bool {
+	if need_whitespace && !emitter.whitespace {
+		if !put(emitter, ' ') {
+			return false
+		}
+	}
+	if !write_all(emitter, indicator) {
+		return false
+	}
+	emitter.whitespace = is_whitespace
+	emitter.indention = (emitter.indention && is_indention)
+	emitter.open_ended = false
+	return true
+}
+
+func yaml_emitter_write_anchor(emitter *yaml_emitter_t, value []byte) bool {
+	if !write_all(emitter, value) {
+		return false
+	}
+	emitter.whitespace = false
+	emitter.indention = false
+	return true
+}
+
+func yaml_emitter_write_tag_handle(emitter *yaml_emitter_t, value []byte) bool {
+	if !emitter.whitespace {
+		if !put(emitter, ' ') {
+			return false
+		}
+	}
+	if !write_all(emitter, value) {
+		return false
+	}
+	emitter.whitespace = false
+	emitter.indention = false
+	return true
+}
+
+func yaml_emitter_write_tag_content(emitter *yaml_emitter_t, value []byte, need_whitespace bool) bool {
+	if need_whitespace && !emitter.whitespace {
+		if !put(emitter, ' ') {
+			return false
+		}
+	}
+	for i := 0; i < len(value); {
+		var must_write bool
+		switch value[i] {
+		case ';', '/', '?', ':', '@', '&', '=', '+', '$', ',', '_', '.', '~', '*', '\'', '(', ')', '[', ']':
+			must_write = true
+		default:
+			must_write = is_alpha(value, i)
+		}
+		if must_write {
+			if !write(emitter, value, &i) {
+				return false
+			}
+		} else {
+			w := width(value[i])
+			for k := 0; k < w; k++ {
+				octet := value[i]
+				i++
+				if !put(emitter, '%') {
+					return false
+				}
+
+				c := octet >> 4
+				if c < 10 {
+					c += '0'
+				} else {
+					c += 'A' - 10
+				}
+				if !put(emitter, c) {
+					return false
+				}
+
+				c = octet & 0x0f
+				if c < 10 {
+					c += '0'
+				} else {
+					c += 'A' - 10
+				}
+				if !put(emitter, c) {
+					return false
+				}
+			}
+		}
+	}
+	emitter.whitespace = false
+	emitter.indention = false
+	return true
+}
+
+func yaml_emitter_write_plain_scalar(emitter *yaml_emitter_t, value []byte, allow_breaks bool) bool {
+	if len(value) > 0 && !emitter.whitespace {
+		if !put(emitter, ' ') {
+			return false
+		}
+	}
+
+	spaces := false
+	breaks := false
+	for i := 0; i < len(value); {
+		if is_space(value, i) {
+			if allow_breaks && !spaces && emitter.column > emitter.best_width && !is_space(value, i+1) {
+				if !yaml_emitter_write_indent(emitter) {
+					return false
+				}
+				i += width(value[i])
+			} else {
+				if !write(emitter, value, &i) {
+					return false
+				}
+			}
+			spaces = true
+		} else if is_break(value, i) {
+			if !breaks && value[i] == '\n' {
+				if !put_break(emitter) {
+					return false
+				}
+			}
+			if !write_break(emitter, value, &i) {
+				return false
+			}
+			//emitter.indention = true
+			breaks = true
+		} else {
+			if breaks {
+				if !yaml_emitter_write_indent(emitter) {
+					return false
+				}
+			}
+			if !write(emitter, value, &i) {
+				return false
+			}
+			emitter.indention = false
+			spaces = false
+			breaks = false
+		}
+	}
+
+	if len(value) > 0 {
+		emitter.whitespace = false
+	}
+	emitter.indention = false
+	if emitter.root_context {
+		emitter.open_ended = true
+	}
+
+	return true
+}
+
+func yaml_emitter_write_single_quoted_scalar(emitter *yaml_emitter_t, value []byte, allow_breaks bool) bool {
+
+	if !yaml_emitter_write_indicator(emitter, []byte{'\''}, true, false, false) {
+		return false
+	}
+
+	spaces := false
+	breaks := false
+	for i := 0; i < len(value); {
+		if is_space(value, i) {
+			if allow_breaks && !spaces && emitter.column > emitter.best_width && i > 0 && i < len(value)-1 && !is_space(value, i+1) {
+				if !yaml_emitter_write_indent(emitter) {
+					return false
+				}
+				i += width(value[i])
+			} else {
+				if !write(emitter, value, &i) {
+					return false
+				}
+			}
+			spaces = true
+		} else if is_break(value, i) {
+			if !breaks && value[i] == '\n' {
+				if !put_break(emitter) {
+					return false
+				}
+			}
+			if !write_break(emitter, value, &i) {
+				return false
+			}
+			//emitter.indention = true
+			breaks = true
+		} else {
+			if breaks {
+				if !yaml_emitter_write_indent(emitter) {
+					return false
+				}
+			}
+			if value[i] == '\'' {
+				if !put(emitter, '\'') {
+					return false
+				}
+			}
+			if !write(emitter, value, &i) {
+				return false
+			}
+			emitter.indention = false
+			spaces = false
+			breaks = false
+		}
+	}
+	if !yaml_emitter_write_indicator(emitter, []byte{'\''}, false, false, false) {
+		return false
+	}
+	emitter.whitespace = false
+	emitter.indention = false
+	return true
+}
+
+func yaml_emitter_write_double_quoted_scalar(emitter *yaml_emitter_t, value []byte, allow_breaks bool) bool {
+	spaces := false
+	if !yaml_emitter_write_indicator(emitter, []byte{'"'}, true, false, false) {
+		return false
+	}
+
+	for i := 0; i < len(value); {
+		if !is_printable(value, i) || (!emitter.unicode && !is_ascii(value, i)) ||
+			is_bom(value, i) || is_break(value, i) ||
+			value[i] == '"' || value[i] == '\\' {
+
+			octet := value[i]
+
+			var w int
+			var v rune
+			switch {
+			case octet&0x80 == 0x00:
+				w, v = 1, rune(octet&0x7F)
+			case octet&0xE0 == 0xC0:
+				w, v = 2, rune(octet&0x1F)
+			case octet&0xF0 == 0xE0:
+				w, v = 3, rune(octet&0x0F)
+			case octet&0xF8 == 0xF0:
+				w, v = 4, rune(octet&0x07)
+			}
+			for k := 1; k < w; k++ {
+				octet = value[i+k]
+				v = (v << 6) + (rune(octet) & 0x3F)
+			}
+			i += w
+
+			if !put(emitter, '\\') {
+				return false
+			}
+
+			var ok bool
+			switch v {
+			case 0x00:
+				ok = put(emitter, '0')
+			case 0x07:
+				ok = put(emitter, 'a')
+			case 0x08:
+				ok = put(emitter, 'b')
+			case 0x09:
+				ok = put(emitter, 't')
+			case 0x0A:
+				ok = put(emitter, 'n')
+			case 0x0b:
+				ok = put(emitter, 'v')
+			case 0x0c:
+				ok = put(emitter, 'f')
+			case 0x0d:
+				ok = put(emitter, 'r')
+			case 0x1b:
+				ok = put(emitter, 'e')
+			case 0x22:
+				ok = put(emitter, '"')
+			case 0x5c:
+				ok = put(emitter, '\\')
+			case 0x85:
+				ok = put(emitter, 'N')
+			case 0xA0:
+				ok = put(emitter, '_')
+			case 0x2028:
+				ok = put(emitter, 'L')
+			case 0x2029:
+				ok = put(emitter, 'P')
+			default:
+				if v <= 0xFF {
+					ok = put(emitter, 'x')
+					w = 2
+				} else if v <= 0xFFFF {
+					ok = put(emitter, 'u')
+					w = 4
+				} else {
+					ok = put(emitter, 'U')
+					w = 8
+				}
+				for k := (w - 1) * 4; ok && k >= 0; k -= 4 {
+					digit := byte((v >> uint(k)) & 0x0F)
+					if digit < 10 {
+						ok = put(emitter, digit+'0')
+					} else {
+						ok = put(emitter, digit+'A'-10)
+					}
+				}
+			}
+			if !ok {
+				return false
+			}
+			spaces = false
+		} else if is_space(value, i) {
+			if allow_breaks && !spaces && emitter.column > emitter.best_width && i > 0 && i < len(value)-1 {
+				if !yaml_emitter_write_indent(emitter) {
+					return false
+				}
+				if is_space(value, i+1) {
+					if !put(emitter, '\\') {
+						return false
+					}
+				}
+				i += width(value[i])
+			} else if !write(emitter, value, &i) {
+				return false
+			}
+			spaces = true
+		} else {
+			if !write(emitter, value, &i) {
+				return false
+			}
+			spaces = false
+		}
+	}
+	if !yaml_emitter_write_indicator(emitter, []byte{'"'}, false, false, false) {
+		return false
+	}
+	emitter.whitespace = false
+	emitter.indention = false
+	return true
+}
+
+func yaml_emitter_write_block_scalar_hints(emitter *yaml_emitter_t, value []byte) bool {
+	if is_space(value, 0) || is_break(value, 0) {
+		indent_hint := []byte{'0' + byte(emitter.best_indent)}
+		if !yaml_emitter_write_indicator(emitter, indent_hint, false, false, false) {
+			return false
+		}
+	}
+
+	emitter.open_ended = false
+
+	var chomp_hint [1]byte
+	if len(value) == 0 {
+		chomp_hint[0] = '-'
+	} else {
+		i := len(value) - 1
+		for value[i]&0xC0 == 0x80 {
+			i--
+		}
+		if !is_break(value, i) {
+			chomp_hint[0] = '-'
+		} else if i == 0 {
+			chomp_hint[0] = '+'
+			emitter.open_ended = true
+		} else {
+			i--
+			for value[i]&0xC0 == 0x80 {
+				i--
+			}
+			if is_break(value, i) {
+				chomp_hint[0] = '+'
+				emitter.open_ended = true
+			}
+		}
+	}
+	if chomp_hint[0] != 0 {
+		if !yaml_emitter_write_indicator(emitter, chomp_hint[:], false, false, false) {
+			return false
+		}
+	}
+	return true
+}
+
+func yaml_emitter_write_literal_scalar(emitter *yaml_emitter_t, value []byte) bool {
+	if !yaml_emitter_write_indicator(emitter, []byte{'|'}, true, false, false) {
+		return false
+	}
+	if !yaml_emitter_write_block_scalar_hints(emitter, value) {
+		return false
+	}
+	if !yaml_emitter_process_line_comment(emitter) {
+		return false
+	}
+	//emitter.indention = true
+	emitter.whitespace = true
+	breaks := true
+	for i := 0; i < len(value); {
+		if is_break(value, i) {
+			if !write_break(emitter, value, &i) {
+				return false
+			}
+			//emitter.indention = true
+			breaks = true
+		} else {
+			if breaks {
+				if !yaml_emitter_write_indent(emitter) {
+					return false
+				}
+			}
+			if !write(emitter, value, &i) {
+				return false
+			}
+			emitter.indention = false
+			breaks = false
+		}
+	}
+
+	return true
+}
+
+func yaml_emitter_write_folded_scalar(emitter *yaml_emitter_t, value []byte) bool {
+	if !yaml_emitter_write_indicator(emitter, []byte{'>'}, true, false, false) {
+		return false
+	}
+	if !yaml_emitter_write_block_scalar_hints(emitter, value) {
+		return false
+	}
+	if !yaml_emitter_process_line_comment(emitter) {
+		return false
+	}
+
+	//emitter.indention = true
+	emitter.whitespace = true
+
+	breaks := true
+	leading_spaces := true
+	for i := 0; i < len(value); {
+		if is_break(value, i) {
+			if !breaks && !leading_spaces && value[i] == '\n' {
+				k := 0
+				for is_break(value, k) {
+					k += width(value[k])
+				}
+				if !is_blankz(value, k) {
+					if !put_break(emitter) {
+						return false
+					}
+				}
+			}
+			if !write_break(emitter, value, &i) {
+				return false
+			}
+			//emitter.indention = true
+			breaks = true
+		} else {
+			if breaks {
+				if !yaml_emitter_write_indent(emitter) {
+					return false
+				}
+				leading_spaces = is_blank(value, i)
+			}
+			if !breaks && is_space(value, i) && !is_space(value, i+1) && emitter.column > emitter.best_width {
+				if !yaml_emitter_write_indent(emitter) {
+					return false
+				}
+				i += width(value[i])
+			} else {
+				if !write(emitter, value, &i) {
+					return false
+				}
+			}
+			emitter.indention = false
+			breaks = false
+		}
+	}
+	return true
+}
+
+func yaml_emitter_write_comment(emitter *yaml_emitter_t, comment []byte) bool {
+	breaks := false
+	pound := false
+	for i := 0; i < len(comment); {
+		if is_break(comment, i) {
+			if !write_break(emitter, comment, &i) {
+				return false
+			}
+			//emitter.indention = true
+			breaks = true
+			pound = false
+		} else {
+			if breaks && !yaml_emitter_write_indent(emitter) {
+				return false
+			}
+			if !pound {
+				if comment[i] != '#' && (!put(emitter, '#') || !put(emitter, ' ')) {
+					return false
+				}
+				pound = true
+			}
+			if !write(emitter, comment, &i) {
+				return false
+			}
+			emitter.indention = false
+			breaks = false
+		}
+	}
+	if !breaks && !put_break(emitter) {
+		return false
+	}
+
+	emitter.whitespace = true
+	//emitter.indention = true
+	return true
+}
diff --git a/vendor/gopkg.in/yaml.v3/encode.go b/vendor/gopkg.in/yaml.v3/encode.go
new file mode 100644
index 000000000000..de9e72a3e638
--- /dev/null
+++ b/vendor/gopkg.in/yaml.v3/encode.go
@@ -0,0 +1,577 @@
+//
+// Copyright (c) 2011-2019 Canonical Ltd
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package yaml
+
+import (
+	"encoding"
+	"fmt"
+	"io"
+	"reflect"
+	"regexp"
+	"sort"
+	"strconv"
+	"strings"
+	"time"
+	"unicode/utf8"
+)
+
+type encoder struct {
+	emitter  yaml_emitter_t
+	event    yaml_event_t
+	out      []byte
+	flow     bool
+	indent   int
+	doneInit bool
+}
+
+func newEncoder() *encoder {
+	e := &encoder{}
+	yaml_emitter_initialize(&e.emitter)
+	yaml_emitter_set_output_string(&e.emitter, &e.out)
+	yaml_emitter_set_unicode(&e.emitter, true)
+	return e
+}
+
+func newEncoderWithWriter(w io.Writer) *encoder {
+	e := &encoder{}
+	yaml_emitter_initialize(&e.emitter)
+	yaml_emitter_set_output_writer(&e.emitter, w)
+	yaml_emitter_set_unicode(&e.emitter, true)
+	return e
+}
+
+func (e *encoder) init() {
+	if e.doneInit {
+		return
+	}
+	if e.indent == 0 {
+		e.indent = 4
+	}
+	e.emitter.best_indent = e.indent
+	yaml_stream_start_event_initialize(&e.event, yaml_UTF8_ENCODING)
+	e.emit()
+	e.doneInit = true
+}
+
+func (e *encoder) finish() {
+	e.emitter.open_ended = false
+	yaml_stream_end_event_initialize(&e.event)
+	e.emit()
+}
+
+func (e *encoder) destroy() {
+	yaml_emitter_delete(&e.emitter)
+}
+
+func (e *encoder) emit() {
+	// This will internally delete the e.event value.
+	e.must(yaml_emitter_emit(&e.emitter, &e.event))
+}
+
+func (e *encoder) must(ok bool) {
+	if !ok {
+		msg := e.emitter.problem
+		if msg == "" {
+			msg = "unknown problem generating YAML content"
+		}
+		failf("%s", msg)
+	}
+}
+
+func (e *encoder) marshalDoc(tag string, in reflect.Value) {
+	e.init()
+	var node *Node
+	if in.IsValid() {
+		node, _ = in.Interface().(*Node)
+	}
+	if node != nil && node.Kind == DocumentNode {
+		e.nodev(in)
+	} else {
+		yaml_document_start_event_initialize(&e.event, nil, nil, true)
+		e.emit()
+		e.marshal(tag, in)
+		yaml_document_end_event_initialize(&e.event, true)
+		e.emit()
+	}
+}
+
+func (e *encoder) marshal(tag string, in reflect.Value) {
+	tag = shortTag(tag)
+	if !in.IsValid() || in.Kind() == reflect.Ptr && in.IsNil() {
+		e.nilv()
+		return
+	}
+	iface := in.Interface()
+	switch value := iface.(type) {
+	case *Node:
+		e.nodev(in)
+		return
+	case Node:
+		if !in.CanAddr() {
+			var n = reflect.New(in.Type()).Elem()
+			n.Set(in)
+			in = n
+		}
+		e.nodev(in.Addr())
+		return
+	case time.Time:
+		e.timev(tag, in)
+		return
+	case *time.Time:
+		e.timev(tag, in.Elem())
+		return
+	case time.Duration:
+		e.stringv(tag, reflect.ValueOf(value.String()))
+		return
+	case Marshaler:
+		v, err := value.MarshalYAML()
+		if err != nil {
+			fail(err)
+		}
+		if v == nil {
+			e.nilv()
+			return
+		}
+		e.marshal(tag, reflect.ValueOf(v))
+		return
+	case encoding.TextMarshaler:
+		text, err := value.MarshalText()
+		if err != nil {
+			fail(err)
+		}
+		in = reflect.ValueOf(string(text))
+	case nil:
+		e.nilv()
+		return
+	}
+	switch in.Kind() {
+	case reflect.Interface:
+		e.marshal(tag, in.Elem())
+	case reflect.Map:
+		e.mapv(tag, in)
+	case reflect.Ptr:
+		e.marshal(tag, in.Elem())
+	case reflect.Struct:
+		e.structv(tag, in)
+	case reflect.Slice, reflect.Array:
+		e.slicev(tag, in)
+	case reflect.String:
+		e.stringv(tag, in)
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		e.intv(tag, in)
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+		e.uintv(tag, in)
+	case reflect.Float32, reflect.Float64:
+		e.floatv(tag, in)
+	case reflect.Bool:
+		e.boolv(tag, in)
+	default:
+		panic("cannot marshal type: " + in.Type().String())
+	}
+}
+
+func (e *encoder) mapv(tag string, in reflect.Value) {
+	e.mappingv(tag, func() {
+		keys := keyList(in.MapKeys())
+		sort.Sort(keys)
+		for _, k := range keys {
+			e.marshal("", k)
+			e.marshal("", in.MapIndex(k))
+		}
+	})
+}
+
+func (e *encoder) fieldByIndex(v reflect.Value, index []int) (field reflect.Value) {
+	for _, num := range index {
+		for {
+			if v.Kind() == reflect.Ptr {
+				if v.IsNil() {
+					return reflect.Value{}
+				}
+				v = v.Elem()
+				continue
+			}
+			break
+		}
+		v = v.Field(num)
+	}
+	return v
+}
+
+func (e *encoder) structv(tag string, in reflect.Value) {
+	sinfo, err := getStructInfo(in.Type())
+	if err != nil {
+		panic(err)
+	}
+	e.mappingv(tag, func() {
+		for _, info := range sinfo.FieldsList {
+			var value reflect.Value
+			if info.Inline == nil {
+				value = in.Field(info.Num)
+			} else {
+				value = e.fieldByIndex(in, info.Inline)
+				if !value.IsValid() {
+					continue
+				}
+			}
+			if info.OmitEmpty && isZero(value) {
+				continue
+			}
+			e.marshal("", reflect.ValueOf(info.Key))
+			e.flow = info.Flow
+			e.marshal("", value)
+		}
+		if sinfo.InlineMap >= 0 {
+			m := in.Field(sinfo.InlineMap)
+			if m.Len() > 0 {
+				e.flow = false
+				keys := keyList(m.MapKeys())
+				sort.Sort(keys)
+				for _, k := range keys {
+					if _, found := sinfo.FieldsMap[k.String()]; found {
+						panic(fmt.Sprintf("cannot have key %q in inlined map: conflicts with struct field", k.String()))
+					}
+					e.marshal("", k)
+					e.flow = false
+					e.marshal("", m.MapIndex(k))
+				}
+			}
+		}
+	})
+}
+
+func (e *encoder) mappingv(tag string, f func()) {
+	implicit := tag == ""
+	style := yaml_BLOCK_MAPPING_STYLE
+	if e.flow {
+		e.flow = false
+		style = yaml_FLOW_MAPPING_STYLE
+	}
+	yaml_mapping_start_event_initialize(&e.event, nil, []byte(tag), implicit, style)
+	e.emit()
+	f()
+	yaml_mapping_end_event_initialize(&e.event)
+	e.emit()
+}
+
+func (e *encoder) slicev(tag string, in reflect.Value) {
+	implicit := tag == ""
+	style := yaml_BLOCK_SEQUENCE_STYLE
+	if e.flow {
+		e.flow = false
+		style = yaml_FLOW_SEQUENCE_STYLE
+	}
+	e.must(yaml_sequence_start_event_initialize(&e.event, nil, []byte(tag), implicit, style))
+	e.emit()
+	n := in.Len()
+	for i := 0; i < n; i++ {
+		e.marshal("", in.Index(i))
+	}
+	e.must(yaml_sequence_end_event_initialize(&e.event))
+	e.emit()
+}
+
+// isBase60 returns whether s is in base 60 notation as defined in YAML 1.1.
+//
+// The base 60 float notation in YAML 1.1 is a terrible idea and is unsupported
+// in YAML 1.2 and by this package, but these should be marshalled quoted for
+// the time being for compatibility with other parsers.
+func isBase60Float(s string) (result bool) {
+	// Fast path.
+	if s == "" {
+		return false
+	}
+	c := s[0]
+	if !(c == '+' || c == '-' || c >= '0' && c <= '9') || strings.IndexByte(s, ':') < 0 {
+		return false
+	}
+	// Do the full match.
+	return base60float.MatchString(s)
+}
+
+// From http://yaml.org/type/float.html, except the regular expression there
+// is bogus. In practice parsers do not enforce the "\.[0-9_]*" suffix.
+var base60float = regexp.MustCompile(`^[-+]?[0-9][0-9_]*(?::[0-5]?[0-9])+(?:\.[0-9_]*)?$`)
+
+// isOldBool returns whether s is bool notation as defined in YAML 1.1.
+//
+// We continue to force strings that YAML 1.1 would interpret as booleans to be
+// rendered as quotes strings so that the marshalled output valid for YAML 1.1
+// parsing.
+func isOldBool(s string) (result bool) {
+	switch s {
+	case "y", "Y", "yes", "Yes", "YES", "on", "On", "ON",
+		"n", "N", "no", "No", "NO", "off", "Off", "OFF":
+		return true
+	default:
+		return false
+	}
+}
+
+func (e *encoder) stringv(tag string, in reflect.Value) {
+	var style yaml_scalar_style_t
+	s := in.String()
+	canUsePlain := true
+	switch {
+	case !utf8.ValidString(s):
+		if tag == binaryTag {
+			failf("explicitly tagged !!binary data must be base64-encoded")
+		}
+		if tag != "" {
+			failf("cannot marshal invalid UTF-8 data as %s", shortTag(tag))
+		}
+		// It can't be encoded directly as YAML so use a binary tag
+		// and encode it as base64.
+		tag = binaryTag
+		s = encodeBase64(s)
+	case tag == "":
+		// Check to see if it would resolve to a specific
+		// tag when encoded unquoted. If it doesn't,
+		// there's no need to quote it.
+		rtag, _ := resolve("", s)
+		canUsePlain = rtag == strTag && !(isBase60Float(s) || isOldBool(s))
+	}
+	// Note: it's possible for user code to emit invalid YAML
+	// if they explicitly specify a tag and a string containing
+	// text that's incompatible with that tag.
+	switch {
+	case strings.Contains(s, "\n"):
+		if e.flow {
+			style = yaml_DOUBLE_QUOTED_SCALAR_STYLE
+		} else {
+			style = yaml_LITERAL_SCALAR_STYLE
+		}
+	case canUsePlain:
+		style = yaml_PLAIN_SCALAR_STYLE
+	default:
+		style = yaml_DOUBLE_QUOTED_SCALAR_STYLE
+	}
+	e.emitScalar(s, "", tag, style, nil, nil, nil, nil)
+}
+
+func (e *encoder) boolv(tag string, in reflect.Value) {
+	var s string
+	if in.Bool() {
+		s = "true"
+	} else {
+		s = "false"
+	}
+	e.emitScalar(s, "", tag, yaml_PLAIN_SCALAR_STYLE, nil, nil, nil, nil)
+}
+
+func (e *encoder) intv(tag string, in reflect.Value) {
+	s := strconv.FormatInt(in.Int(), 10)
+	e.emitScalar(s, "", tag, yaml_PLAIN_SCALAR_STYLE, nil, nil, nil, nil)
+}
+
+func (e *encoder) uintv(tag string, in reflect.Value) {
+	s := strconv.FormatUint(in.Uint(), 10)
+	e.emitScalar(s, "", tag, yaml_PLAIN_SCALAR_STYLE, nil, nil, nil, nil)
+}
+
+func (e *encoder) timev(tag string, in reflect.Value) {
+	t := in.Interface().(time.Time)
+	s := t.Format(time.RFC3339Nano)
+	e.emitScalar(s, "", tag, yaml_PLAIN_SCALAR_STYLE, nil, nil, nil, nil)
+}
+
+func (e *encoder) floatv(tag string, in reflect.Value) {
+	// Issue #352: When formatting, use the precision of the underlying value
+	precision := 64
+	if in.Kind() == reflect.Float32 {
+		precision = 32
+	}
+
+	s := strconv.FormatFloat(in.Float(), 'g', -1, precision)
+	switch s {
+	case "+Inf":
+		s = ".inf"
+	case "-Inf":
+		s = "-.inf"
+	case "NaN":
+		s = ".nan"
+	}
+	e.emitScalar(s, "", tag, yaml_PLAIN_SCALAR_STYLE, nil, nil, nil, nil)
+}
+
+func (e *encoder) nilv() {
+	e.emitScalar("null", "", "", yaml_PLAIN_SCALAR_STYLE, nil, nil, nil, nil)
+}
+
+func (e *encoder) emitScalar(value, anchor, tag string, style yaml_scalar_style_t, head, line, foot, tail []byte) {
+	// TODO Kill this function. Replace all initialize calls by their underlining Go literals.
+	implicit := tag == ""
+	if !implicit {
+		tag = longTag(tag)
+	}
+	e.must(yaml_scalar_event_initialize(&e.event, []byte(anchor), []byte(tag), []byte(value), implicit, implicit, style))
+	e.event.head_comment = head
+	e.event.line_comment = line
+	e.event.foot_comment = foot
+	e.event.tail_comment = tail
+	e.emit()
+}
+
+func (e *encoder) nodev(in reflect.Value) {
+	e.node(in.Interface().(*Node), "")
+}
+
+func (e *encoder) node(node *Node, tail string) {
+	// Zero nodes behave as nil.
+	if node.Kind == 0 && node.IsZero() {
+		e.nilv()
+		return
+	}
+
+	// If the tag was not explicitly requested, and dropping it won't change the
+	// implicit tag of the value, don't include it in the presentation.
+	var tag = node.Tag
+	var stag = shortTag(tag)
+	var forceQuoting bool
+	if tag != "" && node.Style&TaggedStyle == 0 {
+		if node.Kind == ScalarNode {
+			if stag == strTag && node.Style&(SingleQuotedStyle|DoubleQuotedStyle|LiteralStyle|FoldedStyle) != 0 {
+				tag = ""
+			} else {
+				rtag, _ := resolve("", node.Value)
+				if rtag == stag {
+					tag = ""
+				} else if stag == strTag {
+					tag = ""
+					forceQuoting = true
+				}
+			}
+		} else {
+			var rtag string
+			switch node.Kind {
+			case MappingNode:
+				rtag = mapTag
+			case SequenceNode:
+				rtag = seqTag
+			}
+			if rtag == stag {
+				tag = ""
+			}
+		}
+	}
+
+	switch node.Kind {
+	case DocumentNode:
+		yaml_document_start_event_initialize(&e.event, nil, nil, true)
+		e.event.head_comment = []byte(node.HeadComment)
+		e.emit()
+		for _, node := range node.Content {
+			e.node(node, "")
+		}
+		yaml_document_end_event_initialize(&e.event, true)
+		e.event.foot_comment = []byte(node.FootComment)
+		e.emit()
+
+	case SequenceNode:
+		style := yaml_BLOCK_SEQUENCE_STYLE
+		if node.Style&FlowStyle != 0 {
+			style = yaml_FLOW_SEQUENCE_STYLE
+		}
+		e.must(yaml_sequence_start_event_initialize(&e.event, []byte(node.Anchor), []byte(longTag(tag)), tag == "", style))
+		e.event.head_comment = []byte(node.HeadComment)
+		e.emit()
+		for _, node := range node.Content {
+			e.node(node, "")
+		}
+		e.must(yaml_sequence_end_event_initialize(&e.event))
+		e.event.line_comment = []byte(node.LineComment)
+		e.event.foot_comment = []byte(node.FootComment)
+		e.emit()
+
+	case MappingNode:
+		style := yaml_BLOCK_MAPPING_STYLE
+		if node.Style&FlowStyle != 0 {
+			style = yaml_FLOW_MAPPING_STYLE
+		}
+		yaml_mapping_start_event_initialize(&e.event, []byte(node.Anchor), []byte(longTag(tag)), tag == "", style)
+		e.event.tail_comment = []byte(tail)
+		e.event.head_comment = []byte(node.HeadComment)
+		e.emit()
+
+		// The tail logic below moves the foot comment of prior keys to the following key,
+		// since the value for each key may be a nested structure and the foot needs to be
+		// processed only the entirety of the value is streamed. The last tail is processed
+		// with the mapping end event.
+		var tail string
+		for i := 0; i+1 < len(node.Content); i += 2 {
+			k := node.Content[i]
+			foot := k.FootComment
+			if foot != "" {
+				kopy := *k
+				kopy.FootComment = ""
+				k = &kopy
+			}
+			e.node(k, tail)
+			tail = foot
+
+			v := node.Content[i+1]
+			e.node(v, "")
+		}
+
+		yaml_mapping_end_event_initialize(&e.event)
+		e.event.tail_comment = []byte(tail)
+		e.event.line_comment = []byte(node.LineComment)
+		e.event.foot_comment = []byte(node.FootComment)
+		e.emit()
+
+	case AliasNode:
+		yaml_alias_event_initialize(&e.event, []byte(node.Value))
+		e.event.head_comment = []byte(node.HeadComment)
+		e.event.line_comment = []byte(node.LineComment)
+		e.event.foot_comment = []byte(node.FootComment)
+		e.emit()
+
+	case ScalarNode:
+		value := node.Value
+		if !utf8.ValidString(value) {
+			if stag == binaryTag {
+				failf("explicitly tagged !!binary data must be base64-encoded")
+			}
+			if stag != "" {
+				failf("cannot marshal invalid UTF-8 data as %s", stag)
+			}
+			// It can't be encoded directly as YAML so use a binary tag
+			// and encode it as base64.
+			tag = binaryTag
+			value = encodeBase64(value)
+		}
+
+		style := yaml_PLAIN_SCALAR_STYLE
+		switch {
+		case node.Style&DoubleQuotedStyle != 0:
+			style = yaml_DOUBLE_QUOTED_SCALAR_STYLE
+		case node.Style&SingleQuotedStyle != 0:
+			style = yaml_SINGLE_QUOTED_SCALAR_STYLE
+		case node.Style&LiteralStyle != 0:
+			style = yaml_LITERAL_SCALAR_STYLE
+		case node.Style&FoldedStyle != 0:
+			style = yaml_FOLDED_SCALAR_STYLE
+		case strings.Contains(value, "\n"):
+			style = yaml_LITERAL_SCALAR_STYLE
+		case forceQuoting:
+			style = yaml_DOUBLE_QUOTED_SCALAR_STYLE
+		}
+
+		e.emitScalar(value, node.Anchor, tag, style, []byte(node.HeadComment), []byte(node.LineComment), []byte(node.FootComment), []byte(tail))
+	default:
+		failf("cannot encode node with unknown kind %d", node.Kind)
+	}
+}
diff --git a/vendor/gopkg.in/yaml.v3/parserc.go b/vendor/gopkg.in/yaml.v3/parserc.go
new file mode 100644
index 000000000000..268558a0d632
--- /dev/null
+++ b/vendor/gopkg.in/yaml.v3/parserc.go
@@ -0,0 +1,1258 @@
+//
+// Copyright (c) 2011-2019 Canonical Ltd
+// Copyright (c) 2006-2010 Kirill Simonov
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy of
+// this software and associated documentation files (the "Software"), to deal in
+// the Software without restriction, including without limitation the rights to
+// use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+// of the Software, and to permit persons to whom the Software is furnished to do
+// so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+package yaml
+
+import (
+	"bytes"
+)
+
+// The parser implements the following grammar:
+//
+// stream               ::= STREAM-START implicit_document? explicit_document* STREAM-END
+// implicit_document    ::= block_node DOCUMENT-END*
+// explicit_document    ::= DIRECTIVE* DOCUMENT-START block_node? DOCUMENT-END*
+// block_node_or_indentless_sequence    ::=
+//                          ALIAS
+//                          | properties (block_content | indentless_block_sequence)?
+//                          | block_content
+//                          | indentless_block_sequence
+// block_node           ::= ALIAS
+//                          | properties block_content?
+//                          | block_content
+// flow_node            ::= ALIAS
+//                          | properties flow_content?
+//                          | flow_content
+// properties           ::= TAG ANCHOR? | ANCHOR TAG?
+// block_content        ::= block_collection | flow_collection | SCALAR
+// flow_content         ::= flow_collection | SCALAR
+// block_collection     ::= block_sequence | block_mapping
+// flow_collection      ::= flow_sequence | flow_mapping
+// block_sequence       ::= BLOCK-SEQUENCE-START (BLOCK-ENTRY block_node?)* BLOCK-END
+// indentless_sequence  ::= (BLOCK-ENTRY block_node?)+
+// block_mapping        ::= BLOCK-MAPPING_START
+//                          ((KEY block_node_or_indentless_sequence?)?
+//                          (VALUE block_node_or_indentless_sequence?)?)*
+//                          BLOCK-END
+// flow_sequence        ::= FLOW-SEQUENCE-START
+//                          (flow_sequence_entry FLOW-ENTRY)*
+//                          flow_sequence_entry?
+//                          FLOW-SEQUENCE-END
+// flow_sequence_entry  ::= flow_node | KEY flow_node? (VALUE flow_node?)?
+// flow_mapping         ::= FLOW-MAPPING-START
+//                          (flow_mapping_entry FLOW-ENTRY)*
+//                          flow_mapping_entry?
+//                          FLOW-MAPPING-END
+// flow_mapping_entry   ::= flow_node | KEY flow_node? (VALUE flow_node?)?
+
+// Peek the next token in the token queue.
+func peek_token(parser *yaml_parser_t) *yaml_token_t {
+	if parser.token_available || yaml_parser_fetch_more_tokens(parser) {
+		token := &parser.tokens[parser.tokens_head]
+		yaml_parser_unfold_comments(parser, token)
+		return token
+	}
+	return nil
+}
+
+// yaml_parser_unfold_comments walks through the comments queue and joins all
+// comments behind the position of the provided token into the respective
+// top-level comment slices in the parser.
+func yaml_parser_unfold_comments(parser *yaml_parser_t, token *yaml_token_t) {
+	for parser.comments_head < len(parser.comments) && token.start_mark.index >= parser.comments[parser.comments_head].token_mark.index {
+		comment := &parser.comments[parser.comments_head]
+		if len(comment.head) > 0 {
+			if token.typ == yaml_BLOCK_END_TOKEN {
+				// No heads on ends, so keep comment.head for a follow up token.
+				break
+			}
+			if len(parser.head_comment) > 0 {
+				parser.head_comment = append(parser.head_comment, '\n')
+			}
+			parser.head_comment = append(parser.head_comment, comment.head...)
+		}
+		if len(comment.foot) > 0 {
+			if len(parser.foot_comment) > 0 {
+				parser.foot_comment = append(parser.foot_comment, '\n')
+			}
+			parser.foot_comment = append(parser.foot_comment, comment.foot...)
+		}
+		if len(comment.line) > 0 {
+			if len(parser.line_comment) > 0 {
+				parser.line_comment = append(parser.line_comment, '\n')
+			}
+			parser.line_comment = append(parser.line_comment, comment.line...)
+		}
+		*comment = yaml_comment_t{}
+		parser.comments_head++
+	}
+}
+
+// Remove the next token from the queue (must be called after peek_token).
+func skip_token(parser *yaml_parser_t) {
+	parser.token_available = false
+	parser.tokens_parsed++
+	parser.stream_end_produced = parser.tokens[parser.tokens_head].typ == yaml_STREAM_END_TOKEN
+	parser.tokens_head++
+}
+
+// Get the next event.
+func yaml_parser_parse(parser *yaml_parser_t, event *yaml_event_t) bool {
+	// Erase the event object.
+	*event = yaml_event_t{}
+
+	// No events after the end of the stream or error.
+	if parser.stream_end_produced || parser.error != yaml_NO_ERROR || parser.state == yaml_PARSE_END_STATE {
+		return true
+	}
+
+	// Generate the next event.
+	return yaml_parser_state_machine(parser, event)
+}
+
+// Set parser error.
+func yaml_parser_set_parser_error(parser *yaml_parser_t, problem string, problem_mark yaml_mark_t) bool {
+	parser.error = yaml_PARSER_ERROR
+	parser.problem = problem
+	parser.problem_mark = problem_mark
+	return false
+}
+
+func yaml_parser_set_parser_error_context(parser *yaml_parser_t, context string, context_mark yaml_mark_t, problem string, problem_mark yaml_mark_t) bool {
+	parser.error = yaml_PARSER_ERROR
+	parser.context = context
+	parser.context_mark = context_mark
+	parser.problem = problem
+	parser.problem_mark = problem_mark
+	return false
+}
+
+// State dispatcher.
+func yaml_parser_state_machine(parser *yaml_parser_t, event *yaml_event_t) bool {
+	//trace("yaml_parser_state_machine", "state:", parser.state.String())
+
+	switch parser.state {
+	case yaml_PARSE_STREAM_START_STATE:
+		return yaml_parser_parse_stream_start(parser, event)
+
+	case yaml_PARSE_IMPLICIT_DOCUMENT_START_STATE:
+		return yaml_parser_parse_document_start(parser, event, true)
+
+	case yaml_PARSE_DOCUMENT_START_STATE:
+		return yaml_parser_parse_document_start(parser, event, false)
+
+	case yaml_PARSE_DOCUMENT_CONTENT_STATE:
+		return yaml_parser_parse_document_content(parser, event)
+
+	case yaml_PARSE_DOCUMENT_END_STATE:
+		return yaml_parser_parse_document_end(parser, event)
+
+	case yaml_PARSE_BLOCK_NODE_STATE:
+		return yaml_parser_parse_node(parser, event, true, false)
+
+	case yaml_PARSE_BLOCK_NODE_OR_INDENTLESS_SEQUENCE_STATE:
+		return yaml_parser_parse_node(parser, event, true, true)
+
+	case yaml_PARSE_FLOW_NODE_STATE:
+		return yaml_parser_parse_node(parser, event, false, false)
+
+	case yaml_PARSE_BLOCK_SEQUENCE_FIRST_ENTRY_STATE:
+		return yaml_parser_parse_block_sequence_entry(parser, event, true)
+
+	case yaml_PARSE_BLOCK_SEQUENCE_ENTRY_STATE:
+		return yaml_parser_parse_block_sequence_entry(parser, event, false)
+
+	case yaml_PARSE_INDENTLESS_SEQUENCE_ENTRY_STATE:
+		return yaml_parser_parse_indentless_sequence_entry(parser, event)
+
+	case yaml_PARSE_BLOCK_MAPPING_FIRST_KEY_STATE:
+		return yaml_parser_parse_block_mapping_key(parser, event, true)
+
+	case yaml_PARSE_BLOCK_MAPPING_KEY_STATE:
+		return yaml_parser_parse_block_mapping_key(parser, event, false)
+
+	case yaml_PARSE_BLOCK_MAPPING_VALUE_STATE:
+		return yaml_parser_parse_block_mapping_value(parser, event)
+
+	case yaml_PARSE_FLOW_SEQUENCE_FIRST_ENTRY_STATE:
+		return yaml_parser_parse_flow_sequence_entry(parser, event, true)
+
+	case yaml_PARSE_FLOW_SEQUENCE_ENTRY_STATE:
+		return yaml_parser_parse_flow_sequence_entry(parser, event, false)
+
+	case yaml_PARSE_FLOW_SEQUENCE_ENTRY_MAPPING_KEY_STATE:
+		return yaml_parser_parse_flow_sequence_entry_mapping_key(parser, event)
+
+	case yaml_PARSE_FLOW_SEQUENCE_ENTRY_MAPPING_VALUE_STATE:
+		return yaml_parser_parse_flow_sequence_entry_mapping_value(parser, event)
+
+	case yaml_PARSE_FLOW_SEQUENCE_ENTRY_MAPPING_END_STATE:
+		return yaml_parser_parse_flow_sequence_entry_mapping_end(parser, event)
+
+	case yaml_PARSE_FLOW_MAPPING_FIRST_KEY_STATE:
+		return yaml_parser_parse_flow_mapping_key(parser, event, true)
+
+	case yaml_PARSE_FLOW_MAPPING_KEY_STATE:
+		return yaml_parser_parse_flow_mapping_key(parser, event, false)
+
+	case yaml_PARSE_FLOW_MAPPING_VALUE_STATE:
+		return yaml_parser_parse_flow_mapping_value(parser, event, false)
+
+	case yaml_PARSE_FLOW_MAPPING_EMPTY_VALUE_STATE:
+		return yaml_parser_parse_flow_mapping_value(parser, event, true)
+
+	default:
+		panic("invalid parser state")
+	}
+}
+
+// Parse the production:
+// stream   ::= STREAM-START implicit_document? explicit_document* STREAM-END
+//              ************
+func yaml_parser_parse_stream_start(parser *yaml_parser_t, event *yaml_event_t) bool {
+	token := peek_token(parser)
+	if token == nil {
+		return false
+	}
+	if token.typ != yaml_STREAM_START_TOKEN {
+		return yaml_parser_set_parser_error(parser, "did not find expected <stream-start>", token.start_mark)
+	}
+	parser.state = yaml_PARSE_IMPLICIT_DOCUMENT_START_STATE
+	*event = yaml_event_t{
+		typ:        yaml_STREAM_START_EVENT,
+		start_mark: token.start_mark,
+		end_mark:   token.end_mark,
+		encoding:   token.encoding,
+	}
+	skip_token(parser)
+	return true
+}
+
+// Parse the productions:
+// implicit_document    ::= block_node DOCUMENT-END*
+//                          *
+// explicit_document    ::= DIRECTIVE* DOCUMENT-START block_node? DOCUMENT-END*
+//                          *************************
+func yaml_parser_parse_document_start(parser *yaml_parser_t, event *yaml_event_t, implicit bool) bool {
+
+	token := peek_token(parser)
+	if token == nil {
+		return false
+	}
+
+	// Parse extra document end indicators.
+	if !implicit {
+		for token.typ == yaml_DOCUMENT_END_TOKEN {
+			skip_token(parser)
+			token = peek_token(parser)
+			if token == nil {
+				return false
+			}
+		}
+	}
+
+	if implicit && token.typ != yaml_VERSION_DIRECTIVE_TOKEN &&
+		token.typ != yaml_TAG_DIRECTIVE_TOKEN &&
+		token.typ != yaml_DOCUMENT_START_TOKEN &&
+		token.typ != yaml_STREAM_END_TOKEN {
+		// Parse an implicit document.
+		if !yaml_parser_process_directives(parser, nil, nil) {
+			return false
+		}
+		parser.states = append(parser.states, yaml_PARSE_DOCUMENT_END_STATE)
+		parser.state = yaml_PARSE_BLOCK_NODE_STATE
+
+		var head_comment []byte
+		if len(parser.head_comment) > 0 {
+			// [Go] Scan the header comment backwards, and if an empty line is found, break
+			//      the header so the part before the last empty line goes into the
+			//      document header, while the bottom of it goes into a follow up event.
+			for i := len(parser.head_comment) - 1; i > 0; i-- {
+				if parser.head_comment[i] == '\n' {
+					if i == len(parser.head_comment)-1 {
+						head_comment = parser.head_comment[:i]
+						parser.head_comment = parser.head_comment[i+1:]
+						break
+					} else if parser.head_comment[i-1] == '\n' {
+						head_comment = parser.head_comment[:i-1]
+						parser.head_comment = parser.head_comment[i+1:]
+						break
+					}
+				}
+			}
+		}
+
+		*event = yaml_event_t{
+			typ:        yaml_DOCUMENT_START_EVENT,
+			start_mark: token.start_mark,
+			end_mark:   token.end_mark,
+
+			head_comment: head_comment,
+		}
+
+	} else if token.typ != yaml_STREAM_END_TOKEN {
+		// Parse an explicit document.
+		var version_directive *yaml_version_directive_t
+		var tag_directives []yaml_tag_directive_t
+		start_mark := token.start_mark
+		if !yaml_parser_process_directives(parser, &version_directive, &tag_directives) {
+			return false
+		}
+		token = peek_token(parser)
+		if token == nil {
+			return false
+		}
+		if token.typ != yaml_DOCUMENT_START_TOKEN {
+			yaml_parser_set_parser_error(parser,
+				"did not find expected <document start>", token.start_mark)
+			return false
+		}
+		parser.states = append(parser.states, yaml_PARSE_DOCUMENT_END_STATE)
+		parser.state = yaml_PARSE_DOCUMENT_CONTENT_STATE
+		end_mark := token.end_mark
+
+		*event = yaml_event_t{
+			typ:               yaml_DOCUMENT_START_EVENT,
+			start_mark:        start_mark,
+			end_mark:          end_mark,
+			version_directive: version_directive,
+			tag_directives:    tag_directives,
+			implicit:          false,
+		}
+		skip_token(parser)
+
+	} else {
+		// Parse the stream end.
+		parser.state = yaml_PARSE_END_STATE
+		*event = yaml_event_t{
+			typ:        yaml_STREAM_END_EVENT,
+			start_mark: token.start_mark,
+			end_mark:   token.end_mark,
+		}
+		skip_token(parser)
+	}
+
+	return true
+}
+
+// Parse the productions:
+// explicit_document    ::= DIRECTIVE* DOCUMENT-START block_node? DOCUMENT-END*
+//                                                    ***********
+//
+func yaml_parser_parse_document_content(parser *yaml_parser_t, event *yaml_event_t) bool {
+	token := peek_token(parser)
+	if token == nil {
+		return false
+	}
+
+	if token.typ == yaml_VERSION_DIRECTIVE_TOKEN ||
+		token.typ == yaml_TAG_DIRECTIVE_TOKEN ||
+		token.typ == yaml_DOCUMENT_START_TOKEN ||
+		token.typ == yaml_DOCUMENT_END_TOKEN ||
+		token.typ == yaml_STREAM_END_TOKEN {
+		parser.state = parser.states[len(parser.states)-1]
+		parser.states = parser.states[:len(parser.states)-1]
+		return yaml_parser_process_empty_scalar(parser, event,
+			token.start_mark)
+	}
+	return yaml_parser_parse_node(parser, event, true, false)
+}
+
+// Parse the productions:
+// implicit_document    ::= block_node DOCUMENT-END*
+//                                     *************
+// explicit_document    ::= DIRECTIVE* DOCUMENT-START block_node? DOCUMENT-END*
+//
+func yaml_parser_parse_document_end(parser *yaml_parser_t, event *yaml_event_t) bool {
+	token := peek_token(parser)
+	if token == nil {
+		return false
+	}
+
+	start_mark := token.start_mark
+	end_mark := token.start_mark
+
+	implicit := true
+	if token.typ == yaml_DOCUMENT_END_TOKEN {
+		end_mark = token.end_mark
+		skip_token(parser)
+		implicit = false
+	}
+
+	parser.tag_directives = parser.tag_directives[:0]
+
+	parser.state = yaml_PARSE_DOCUMENT_START_STATE
+	*event = yaml_event_t{
+		typ:        yaml_DOCUMENT_END_EVENT,
+		start_mark: start_mark,
+		end_mark:   end_mark,
+		implicit:   implicit,
+	}
+	yaml_parser_set_event_comments(parser, event)
+	if len(event.head_comment) > 0 && len(event.foot_comment) == 0 {
+		event.foot_comment = event.head_comment
+		event.head_comment = nil
+	}
+	return true
+}
+
+func yaml_parser_set_event_comments(parser *yaml_parser_t, event *yaml_event_t) {
+	event.head_comment = parser.head_comment
+	event.line_comment = parser.line_comment
+	event.foot_comment = parser.foot_comment
+	parser.head_comment = nil
+	parser.line_comment = nil
+	parser.foot_comment = nil
+	parser.tail_comment = nil
+	parser.stem_comment = nil
+}
+
+// Parse the productions:
+// block_node_or_indentless_sequence    ::=
+//                          ALIAS
+//                          *****
+//                          | properties (block_content | indentless_block_sequence)?
+//                            **********  *
+//                          | block_content | indentless_block_sequence
+//                            *
+// block_node           ::= ALIAS
+//                          *****
+//                          | properties block_content?
+//                            ********** *
+//                          | block_content
+//                            *
+// flow_node            ::= ALIAS
+//                          *****
+//                          | properties flow_content?
+//                            ********** *
+//                          | flow_content
+//                            *
+// properties           ::= TAG ANCHOR? | ANCHOR TAG?
+//                          *************************
+// block_content        ::= block_collection | flow_collection | SCALAR
+//                                                               ******
+// flow_content         ::= flow_collection | SCALAR
+//                                            ******
+func yaml_parser_parse_node(parser *yaml_parser_t, event *yaml_event_t, block, indentless_sequence bool) bool {
+	//defer trace("yaml_parser_parse_node", "block:", block, "indentless_sequence:", indentless_sequence)()
+
+	token := peek_token(parser)
+	if token == nil {
+		return false
+	}
+
+	if token.typ == yaml_ALIAS_TOKEN {
+		parser.state = parser.states[len(parser.states)-1]
+		parser.states = parser.states[:len(parser.states)-1]
+		*event = yaml_event_t{
+			typ:        yaml_ALIAS_EVENT,
+			start_mark: token.start_mark,
+			end_mark:   token.end_mark,
+			anchor:     token.value,
+		}
+		yaml_parser_set_event_comments(parser, event)
+		skip_token(parser)
+		return true
+	}
+
+	start_mark := token.start_mark
+	end_mark := token.start_mark
+
+	var tag_token bool
+	var tag_handle, tag_suffix, anchor []byte
+	var tag_mark yaml_mark_t
+	if token.typ == yaml_ANCHOR_TOKEN {
+		anchor = token.value
+		start_mark = token.start_mark
+		end_mark = token.end_mark
+		skip_token(parser)
+		token = peek_token(parser)
+		if token == nil {
+			return false
+		}
+		if token.typ == yaml_TAG_TOKEN {
+			tag_token = true
+			tag_handle = token.value
+			tag_suffix = token.suffix
+			tag_mark = token.start_mark
+			end_mark = token.end_mark
+			skip_token(parser)
+			token = peek_token(parser)
+			if token == nil {
+				return false
+			}
+		}
+	} else if token.typ == yaml_TAG_TOKEN {
+		tag_token = true
+		tag_handle = token.value
+		tag_suffix = token.suffix
+		start_mark = token.start_mark
+		tag_mark = token.start_mark
+		end_mark = token.end_mark
+		skip_token(parser)
+		token = peek_token(parser)
+		if token == nil {
+			return false
+		}
+		if token.typ == yaml_ANCHOR_TOKEN {
+			anchor = token.value
+			end_mark = token.end_mark
+			skip_token(parser)
+			token = peek_token(parser)
+			if token == nil {
+				return false
+			}
+		}
+	}
+
+	var tag []byte
+	if tag_token {
+		if len(tag_handle) == 0 {
+			tag = tag_suffix
+			tag_suffix = nil
+		} else {
+			for i := range parser.tag_directives {
+				if bytes.Equal(parser.tag_directives[i].handle, tag_handle) {
+					tag = append([]byte(nil), parser.tag_directives[i].prefix...)
+					tag = append(tag, tag_suffix...)
+					break
+				}
+			}
+			if len(tag) == 0 {
+				yaml_parser_set_parser_error_context(parser,
+					"while parsing a node", start_mark,
+					"found undefined tag handle", tag_mark)
+				return false
+			}
+		}
+	}
+
+	implicit := len(tag) == 0
+	if indentless_sequence && token.typ == yaml_BLOCK_ENTRY_TOKEN {
+		end_mark = token.end_mark
+		parser.state = yaml_PARSE_INDENTLESS_SEQUENCE_ENTRY_STATE
+		*event = yaml_event_t{
+			typ:        yaml_SEQUENCE_START_EVENT,
+			start_mark: start_mark,
+			end_mark:   end_mark,
+			anchor:     anchor,
+			tag:        tag,
+			implicit:   implicit,
+			style:      yaml_style_t(yaml_BLOCK_SEQUENCE_STYLE),
+		}
+		return true
+	}
+	if token.typ == yaml_SCALAR_TOKEN {
+		var plain_implicit, quoted_implicit bool
+		end_mark = token.end_mark
+		if (len(tag) == 0 && token.style == yaml_PLAIN_SCALAR_STYLE) || (len(tag) == 1 && tag[0] == '!') {
+			plain_implicit = true
+		} else if len(tag) == 0 {
+			quoted_implicit = true
+		}
+		parser.state = parser.states[len(parser.states)-1]
+		parser.states = parser.states[:len(parser.states)-1]
+
+		*event = yaml_event_t{
+			typ:             yaml_SCALAR_EVENT,
+			start_mark:      start_mark,
+			end_mark:        end_mark,
+			anchor:          anchor,
+			tag:             tag,
+			value:           token.value,
+			implicit:        plain_implicit,
+			quoted_implicit: quoted_implicit,
+			style:           yaml_style_t(token.style),
+		}
+		yaml_parser_set_event_comments(parser, event)
+		skip_token(parser)
+		return true
+	}
+	if token.typ == yaml_FLOW_SEQUENCE_START_TOKEN {
+		// [Go] Some of the events below can be merged as they differ only on style.
+		end_mark = token.end_mark
+		parser.state = yaml_PARSE_FLOW_SEQUENCE_FIRST_ENTRY_STATE
+		*event = yaml_event_t{
+			typ:        yaml_SEQUENCE_START_EVENT,
+			start_mark: start_mark,
+			end_mark:   end_mark,
+			anchor:     anchor,
+			tag:        tag,
+			implicit:   implicit,
+			style:      yaml_style_t(yaml_FLOW_SEQUENCE_STYLE),
+		}
+		yaml_parser_set_event_comments(parser, event)
+		return true
+	}
+	if token.typ == yaml_FLOW_MAPPING_START_TOKEN {
+		end_mark = token.end_mark
+		parser.state = yaml_PARSE_FLOW_MAPPING_FIRST_KEY_STATE
+		*event = yaml_event_t{
+			typ:        yaml_MAPPING_START_EVENT,
+			start_mark: start_mark,
+			end_mark:   end_mark,
+			anchor:     anchor,
+			tag:        tag,
+			implicit:   implicit,
+			style:      yaml_style_t(yaml_FLOW_MAPPING_STYLE),
+		}
+		yaml_parser_set_event_comments(parser, event)
+		return true
+	}
+	if block && token.typ == yaml_BLOCK_SEQUENCE_START_TOKEN {
+		end_mark = token.end_mark
+		parser.state = yaml_PARSE_BLOCK_SEQUENCE_FIRST_ENTRY_STATE
+		*event = yaml_event_t{
+			typ:        yaml_SEQUENCE_START_EVENT,
+			start_mark: start_mark,
+			end_mark:   end_mark,
+			anchor:     anchor,
+			tag:        tag,
+			implicit:   implicit,
+			style:      yaml_style_t(yaml_BLOCK_SEQUENCE_STYLE),
+		}
+		if parser.stem_comment != nil {
+			event.head_comment = parser.stem_comment
+			parser.stem_comment = nil
+		}
+		return true
+	}
+	if block && token.typ == yaml_BLOCK_MAPPING_START_TOKEN {
+		end_mark = token.end_mark
+		parser.state = yaml_PARSE_BLOCK_MAPPING_FIRST_KEY_STATE
+		*event = yaml_event_t{
+			typ:        yaml_MAPPING_START_EVENT,
+			start_mark: start_mark,
+			end_mark:   end_mark,
+			anchor:     anchor,
+			tag:        tag,
+			implicit:   implicit,
+			style:      yaml_style_t(yaml_BLOCK_MAPPING_STYLE),
+		}
+		if parser.stem_comment != nil {
+			event.head_comment = parser.stem_comment
+			parser.stem_comment = nil
+		}
+		return true
+	}
+	if len(anchor) > 0 || len(tag) > 0 {
+		parser.state = parser.states[len(parser.states)-1]
+		parser.states = parser.states[:len(parser.states)-1]
+
+		*event = yaml_event_t{
+			typ:             yaml_SCALAR_EVENT,
+			start_mark:      start_mark,
+			end_mark:        end_mark,
+			anchor:          anchor,
+			tag:             tag,
+			implicit:        implicit,
+			quoted_implicit: false,
+			style:           yaml_style_t(yaml_PLAIN_SCALAR_STYLE),
+		}
+		return true
+	}
+
+	context := "while parsing a flow node"
+	if block {
+		context = "while parsing a block node"
+	}
+	yaml_parser_set_parser_error_context(parser, context, start_mark,
+		"did not find expected node content", token.start_mark)
+	return false
+}
+
+// Parse the productions:
+// block_sequence ::= BLOCK-SEQUENCE-START (BLOCK-ENTRY block_node?)* BLOCK-END
+//                    ********************  *********** *             *********
+//
+func yaml_parser_parse_block_sequence_entry(parser *yaml_parser_t, event *yaml_event_t, first bool) bool {
+	if first {
+		token := peek_token(parser)
+		if token == nil {
+			return false
+		}
+		parser.marks = append(parser.marks, token.start_mark)
+		skip_token(parser)
+	}
+
+	token := peek_token(parser)
+	if token == nil {
+		return false
+	}
+
+	if token.typ == yaml_BLOCK_ENTRY_TOKEN {
+		mark := token.end_mark
+		prior_head_len := len(parser.head_comment)
+		skip_token(parser)
+		yaml_parser_split_stem_comment(parser, prior_head_len)
+		token = peek_token(parser)
+		if token == nil {
+			return false
+		}
+		if token.typ != yaml_BLOCK_ENTRY_TOKEN && token.typ != yaml_BLOCK_END_TOKEN {
+			parser.states = append(parser.states, yaml_PARSE_BLOCK_SEQUENCE_ENTRY_STATE)
+			return yaml_parser_parse_node(parser, event, true, false)
+		} else {
+			parser.state = yaml_PARSE_BLOCK_SEQUENCE_ENTRY_STATE
+			return yaml_parser_process_empty_scalar(parser, event, mark)
+		}
+	}
+	if token.typ == yaml_BLOCK_END_TOKEN {
+		parser.state = parser.states[len(parser.states)-1]
+		parser.states = parser.states[:len(parser.states)-1]
+		parser.marks = parser.marks[:len(parser.marks)-1]
+
+		*event = yaml_event_t{
+			typ:        yaml_SEQUENCE_END_EVENT,
+			start_mark: token.start_mark,
+			end_mark:   token.end_mark,
+		}
+
+		skip_token(parser)
+		return true
+	}
+
+	context_mark := parser.marks[len(parser.marks)-1]
+	parser.marks = parser.marks[:len(parser.marks)-1]
+	return yaml_parser_set_parser_error_context(parser,
+		"while parsing a block collection", context_mark,
+		"did not find expected '-' indicator", token.start_mark)
+}
+
+// Parse the productions:
+// indentless_sequence  ::= (BLOCK-ENTRY block_node?)+
+//                           *********** *
+func yaml_parser_parse_indentless_sequence_entry(parser *yaml_parser_t, event *yaml_event_t) bool {
+	token := peek_token(parser)
+	if token == nil {
+		return false
+	}
+
+	if token.typ == yaml_BLOCK_ENTRY_TOKEN {
+		mark := token.end_mark
+		prior_head_len := len(parser.head_comment)
+		skip_token(parser)
+		yaml_parser_split_stem_comment(parser, prior_head_len)
+		token = peek_token(parser)
+		if token == nil {
+			return false
+		}
+		if token.typ != yaml_BLOCK_ENTRY_TOKEN &&
+			token.typ != yaml_KEY_TOKEN &&
+			token.typ != yaml_VALUE_TOKEN &&
+			token.typ != yaml_BLOCK_END_TOKEN {
+			parser.states = append(parser.states, yaml_PARSE_INDENTLESS_SEQUENCE_ENTRY_STATE)
+			return yaml_parser_parse_node(parser, event, true, false)
+		}
+		parser.state = yaml_PARSE_INDENTLESS_SEQUENCE_ENTRY_STATE
+		return yaml_parser_process_empty_scalar(parser, event, mark)
+	}
+	parser.state = parser.states[len(parser.states)-1]
+	parser.states = parser.states[:len(parser.states)-1]
+
+	*event = yaml_event_t{
+		typ:        yaml_SEQUENCE_END_EVENT,
+		start_mark: token.start_mark,
+		end_mark:   token.start_mark, // [Go] Shouldn't this be token.end_mark?
+	}
+	return true
+}
+
+// Split stem comment from head comment.
+//
+// When a sequence or map is found under a sequence entry, the former head comment
+// is assigned to the underlying sequence or map as a whole, not the individual
+// sequence or map entry as would be expected otherwise. To handle this case the
+// previous head comment is moved aside as the stem comment.
+func yaml_parser_split_stem_comment(parser *yaml_parser_t, stem_len int) {
+	if stem_len == 0 {
+		return
+	}
+
+	token := peek_token(parser)
+	if token == nil || token.typ != yaml_BLOCK_SEQUENCE_START_TOKEN && token.typ != yaml_BLOCK_MAPPING_START_TOKEN {
+		return
+	}
+
+	parser.stem_comment = parser.head_comment[:stem_len]
+	if len(parser.head_comment) == stem_len {
+		parser.head_comment = nil
+	} else {
+		// Copy suffix to prevent very strange bugs if someone ever appends
+		// further bytes to the prefix in the stem_comment slice above.
+		parser.head_comment = append([]byte(nil), parser.head_comment[stem_len+1:]...)
+	}
+}
+
+// Parse the productions:
+// block_mapping        ::= BLOCK-MAPPING_START
+//                          *******************
+//                          ((KEY block_node_or_indentless_sequence?)?
+//                            *** *
+//                          (VALUE block_node_or_indentless_sequence?)?)*
+//
+//                          BLOCK-END
+//                          *********
+//
+func yaml_parser_parse_block_mapping_key(parser *yaml_parser_t, event *yaml_event_t, first bool) bool {
+	if first {
+		token := peek_token(parser)
+		if token == nil {
+			return false
+		}
+		parser.marks = append(parser.marks, token.start_mark)
+		skip_token(parser)
+	}
+
+	token := peek_token(parser)
+	if token == nil {
+		return false
+	}
+
+	// [Go] A tail comment was left from the prior mapping value processed. Emit an event
+	//      as it needs to be processed with that value and not the following key.
+	if len(parser.tail_comment) > 0 {
+		*event = yaml_event_t{
+			typ:          yaml_TAIL_COMMENT_EVENT,
+			start_mark:   token.start_mark,
+			end_mark:     token.end_mark,
+			foot_comment: parser.tail_comment,
+		}
+		parser.tail_comment = nil
+		return true
+	}
+
+	if token.typ == yaml_KEY_TOKEN {
+		mark := token.end_mark
+		skip_token(parser)
+		token = peek_token(parser)
+		if token == nil {
+			return false
+		}
+		if token.typ != yaml_KEY_TOKEN &&
+			token.typ != yaml_VALUE_TOKEN &&
+			token.typ != yaml_BLOCK_END_TOKEN {
+			parser.states = append(parser.states, yaml_PARSE_BLOCK_MAPPING_VALUE_STATE)
+			return yaml_parser_parse_node(parser, event, true, true)
+		} else {
+			parser.state = yaml_PARSE_BLOCK_MAPPING_VALUE_STATE
+			return yaml_parser_process_empty_scalar(parser, event, mark)
+		}
+	} else if token.typ == yaml_BLOCK_END_TOKEN {
+		parser.state = parser.states[len(parser.states)-1]
+		parser.states = parser.states[:len(parser.states)-1]
+		parser.marks = parser.marks[:len(parser.marks)-1]
+		*event = yaml_event_t{
+			typ:        yaml_MAPPING_END_EVENT,
+			start_mark: token.start_mark,
+			end_mark:   token.end_mark,
+		}
+		yaml_parser_set_event_comments(parser, event)
+		skip_token(parser)
+		return true
+	}
+
+	context_mark := parser.marks[len(parser.marks)-1]
+	parser.marks = parser.marks[:len(parser.marks)-1]
+	return yaml_parser_set_parser_error_context(parser,
+		"while parsing a block mapping", context_mark,
+		"did not find expected key", token.start_mark)
+}
+
+// Parse the productions:
+// block_mapping        ::= BLOCK-MAPPING_START
+//
+//                          ((KEY block_node_or_indentless_sequence?)?
+//
+//                          (VALUE block_node_or_indentless_sequence?)?)*
+//                           ***** *
+//                          BLOCK-END
+//
+//
+func yaml_parser_parse_block_mapping_value(parser *yaml_parser_t, event *yaml_event_t) bool {
+	token := peek_token(parser)
+	if token == nil {
+		return false
+	}
+	if token.typ == yaml_VALUE_TOKEN {
+		mark := token.end_mark
+		skip_token(parser)
+		token = peek_token(parser)
+		if token == nil {
+			return false
+		}
+		if token.typ != yaml_KEY_TOKEN &&
+			token.typ != yaml_VALUE_TOKEN &&
+			token.typ != yaml_BLOCK_END_TOKEN {
+			parser.states = append(parser.states, yaml_PARSE_BLOCK_MAPPING_KEY_STATE)
+			return yaml_parser_parse_node(parser, event, true, true)
+		}
+		parser.state = yaml_PARSE_BLOCK_MAPPING_KEY_STATE
+		return yaml_parser_process_empty_scalar(parser, event, mark)
+	}
+	parser.state = yaml_PARSE_BLOCK_MAPPING_KEY_STATE
+	return yaml_parser_process_empty_scalar(parser, event, token.start_mark)
+}
+
+// Parse the productions:
+// flow_sequence        ::= FLOW-SEQUENCE-START
+//                          *******************
+//                          (flow_sequence_entry FLOW-ENTRY)*
+//                           *                   **********
+//                          flow_sequence_entry?
+//                          *
+//                          FLOW-SEQUENCE-END
+//                          *****************
+// flow_sequence_entry  ::= flow_node | KEY flow_node? (VALUE flow_node?)?
+//                          *
+//
+func yaml_parser_parse_flow_sequence_entry(parser *yaml_parser_t, event *yaml_event_t, first bool) bool {
+	if first {
+		token := peek_token(parser)
+		if token == nil {
+			return false
+		}
+		parser.marks = append(parser.marks, token.start_mark)
+		skip_token(parser)
+	}
+	token := peek_token(parser)
+	if token == nil {
+		return false
+	}
+	if token.typ != yaml_FLOW_SEQUENCE_END_TOKEN {
+		if !first {
+			if token.typ == yaml_FLOW_ENTRY_TOKEN {
+				skip_token(parser)
+				token = peek_token(parser)
+				if token == nil {
+					return false
+				}
+			} else {
+				context_mark := parser.marks[len(parser.marks)-1]
+				parser.marks = parser.marks[:len(parser.marks)-1]
+				return yaml_parser_set_parser_error_context(parser,
+					"while parsing a flow sequence", context_mark,
+					"did not find expected ',' or ']'", token.start_mark)
+			}
+		}
+
+		if token.typ == yaml_KEY_TOKEN {
+			parser.state = yaml_PARSE_FLOW_SEQUENCE_ENTRY_MAPPING_KEY_STATE
+			*event = yaml_event_t{
+				typ:        yaml_MAPPING_START_EVENT,
+				start_mark: token.start_mark,
+				end_mark:   token.end_mark,
+				implicit:   true,
+				style:      yaml_style_t(yaml_FLOW_MAPPING_STYLE),
+			}
+			skip_token(parser)
+			return true
+		} else if token.typ != yaml_FLOW_SEQUENCE_END_TOKEN {
+			parser.states = append(parser.states, yaml_PARSE_FLOW_SEQUENCE_ENTRY_STATE)
+			return yaml_parser_parse_node(parser, event, false, false)
+		}
+	}
+
+	parser.state = parser.states[len(parser.states)-1]
+	parser.states = parser.states[:len(parser.states)-1]
+	parser.marks = parser.marks[:len(parser.marks)-1]
+
+	*event = yaml_event_t{
+		typ:        yaml_SEQUENCE_END_EVENT,
+		start_mark: token.start_mark,
+		end_mark:   token.end_mark,
+	}
+	yaml_parser_set_event_comments(parser, event)
+
+	skip_token(parser)
+	return true
+}
+
+//
+// Parse the productions:
+// flow_sequence_entry  ::= flow_node | KEY flow_node? (VALUE flow_node?)?
+//                                      *** *
+//
+func yaml_parser_parse_flow_sequence_entry_mapping_key(parser *yaml_parser_t, event *yaml_event_t) bool {
+	token := peek_token(parser)
+	if token == nil {
+		return false
+	}
+	if token.typ != yaml_VALUE_TOKEN &&
+		token.typ != yaml_FLOW_ENTRY_TOKEN &&
+		token.typ != yaml_FLOW_SEQUENCE_END_TOKEN {
+		parser.states = append(parser.states, yaml_PARSE_FLOW_SEQUENCE_ENTRY_MAPPING_VALUE_STATE)
+		return yaml_parser_parse_node(parser, event, false, false)
+	}
+	mark := token.end_mark
+	skip_token(parser)
+	parser.state = yaml_PARSE_FLOW_SEQUENCE_ENTRY_MAPPING_VALUE_STATE
+	return yaml_parser_process_empty_scalar(parser, event, mark)
+}
+
+// Parse the productions:
+// flow_sequence_entry  ::= flow_node | KEY flow_node? (VALUE flow_node?)?
+//                                                      ***** *
+//
+func yaml_parser_parse_flow_sequence_entry_mapping_value(parser *yaml_parser_t, event *yaml_event_t) bool {
+	token := peek_token(parser)
+	if token == nil {
+		return false
+	}
+	if token.typ == yaml_VALUE_TOKEN {
+		skip_token(parser)
+		token := peek_token(parser)
+		if token == nil {
+			return false
+		}
+		if token.typ != yaml_FLOW_ENTRY_TOKEN && token.typ != yaml_FLOW_SEQUENCE_END_TOKEN {
+			parser.states = append(parser.states, yaml_PARSE_FLOW_SEQUENCE_ENTRY_MAPPING_END_STATE)
+			return yaml_parser_parse_node(parser, event, false, false)
+		}
+	}
+	parser.state = yaml_PARSE_FLOW_SEQUENCE_ENTRY_MAPPING_END_STATE
+	return yaml_parser_process_empty_scalar(parser, event, token.start_mark)
+}
+
+// Parse the productions:
+// flow_sequence_entry  ::= flow_node | KEY flow_node? (VALUE flow_node?)?
+//                                                                      *
+//
+func yaml_parser_parse_flow_sequence_entry_mapping_end(parser *yaml_parser_t, event *yaml_event_t) bool {
+	token := peek_token(parser)
+	if token == nil {
+		return false
+	}
+	parser.state = yaml_PARSE_FLOW_SEQUENCE_ENTRY_STATE
+	*event = yaml_event_t{
+		typ:        yaml_MAPPING_END_EVENT,
+		start_mark: token.start_mark,
+		end_mark:   token.start_mark, // [Go] Shouldn't this be end_mark?
+	}
+	return true
+}
+
+// Parse the productions:
+// flow_mapping         ::= FLOW-MAPPING-START
+//                          ******************
+//                          (flow_mapping_entry FLOW-ENTRY)*
+//                           *                  **********
+//                          flow_mapping_entry?
+//                          ******************
+//                          FLOW-MAPPING-END
+//                          ****************
+// flow_mapping_entry   ::= flow_node | KEY flow_node? (VALUE flow_node?)?
+//                          *           *** *
+//
+func yaml_parser_parse_flow_mapping_key(parser *yaml_parser_t, event *yaml_event_t, first bool) bool {
+	if first {
+		token := peek_token(parser)
+		parser.marks = append(parser.marks, token.start_mark)
+		skip_token(parser)
+	}
+
+	token := peek_token(parser)
+	if token == nil {
+		return false
+	}
+
+	if token.typ != yaml_FLOW_MAPPING_END_TOKEN {
+		if !first {
+			if token.typ == yaml_FLOW_ENTRY_TOKEN {
+				skip_token(parser)
+				token = peek_token(parser)
+				if token == nil {
+					return false
+				}
+			} else {
+				context_mark := parser.marks[len(parser.marks)-1]
+				parser.marks = parser.marks[:len(parser.marks)-1]
+				return yaml_parser_set_parser_error_context(parser,
+					"while parsing a flow mapping", context_mark,
+					"did not find expected ',' or '}'", token.start_mark)
+			}
+		}
+
+		if token.typ == yaml_KEY_TOKEN {
+			skip_token(parser)
+			token = peek_token(parser)
+			if token == nil {
+				return false
+			}
+			if token.typ != yaml_VALUE_TOKEN &&
+				token.typ != yaml_FLOW_ENTRY_TOKEN &&
+				token.typ != yaml_FLOW_MAPPING_END_TOKEN {
+				parser.states = append(parser.states, yaml_PARSE_FLOW_MAPPING_VALUE_STATE)
+				return yaml_parser_parse_node(parser, event, false, false)
+			} else {
+				parser.state = yaml_PARSE_FLOW_MAPPING_VALUE_STATE
+				return yaml_parser_process_empty_scalar(parser, event, token.start_mark)
+			}
+		} else if token.typ != yaml_FLOW_MAPPING_END_TOKEN {
+			parser.states = append(parser.states, yaml_PARSE_FLOW_MAPPING_EMPTY_VALUE_STATE)
+			return yaml_parser_parse_node(parser, event, false, false)
+		}
+	}
+
+	parser.state = parser.states[len(parser.states)-1]
+	parser.states = parser.states[:len(parser.states)-1]
+	parser.marks = parser.marks[:len(parser.marks)-1]
+	*event = yaml_event_t{
+		typ:        yaml_MAPPING_END_EVENT,
+		start_mark: token.start_mark,
+		end_mark:   token.end_mark,
+	}
+	yaml_parser_set_event_comments(parser, event)
+	skip_token(parser)
+	return true
+}
+
+// Parse the productions:
+// flow_mapping_entry   ::= flow_node | KEY flow_node? (VALUE flow_node?)?
+//                                   *                  ***** *
+//
+func yaml_parser_parse_flow_mapping_value(parser *yaml_parser_t, event *yaml_event_t, empty bool) bool {
+	token := peek_token(parser)
+	if token == nil {
+		return false
+	}
+	if empty {
+		parser.state = yaml_PARSE_FLOW_MAPPING_KEY_STATE
+		return yaml_parser_process_empty_scalar(parser, event, token.start_mark)
+	}
+	if token.typ == yaml_VALUE_TOKEN {
+		skip_token(parser)
+		token = peek_token(parser)
+		if token == nil {
+			return false
+		}
+		if token.typ != yaml_FLOW_ENTRY_TOKEN && token.typ != yaml_FLOW_MAPPING_END_TOKEN {
+			parser.states = append(parser.states, yaml_PARSE_FLOW_MAPPING_KEY_STATE)
+			return yaml_parser_parse_node(parser, event, false, false)
+		}
+	}
+	parser.state = yaml_PARSE_FLOW_MAPPING_KEY_STATE
+	return yaml_parser_process_empty_scalar(parser, event, token.start_mark)
+}
+
+// Generate an empty scalar event.
+func yaml_parser_process_empty_scalar(parser *yaml_parser_t, event *yaml_event_t, mark yaml_mark_t) bool {
+	*event = yaml_event_t{
+		typ:        yaml_SCALAR_EVENT,
+		start_mark: mark,
+		end_mark:   mark,
+		value:      nil, // Empty
+		implicit:   true,
+		style:      yaml_style_t(yaml_PLAIN_SCALAR_STYLE),
+	}
+	return true
+}
+
+var default_tag_directives = []yaml_tag_directive_t{
+	{[]byte("!"), []byte("!")},
+	{[]byte("!!"), []byte("tag:yaml.org,2002:")},
+}
+
+// Parse directives.
+func yaml_parser_process_directives(parser *yaml_parser_t,
+	version_directive_ref **yaml_version_directive_t,
+	tag_directives_ref *[]yaml_tag_directive_t) bool {
+
+	var version_directive *yaml_version_directive_t
+	var tag_directives []yaml_tag_directive_t
+
+	token := peek_token(parser)
+	if token == nil {
+		return false
+	}
+
+	for token.typ == yaml_VERSION_DIRECTIVE_TOKEN || token.typ == yaml_TAG_DIRECTIVE_TOKEN {
+		if token.typ == yaml_VERSION_DIRECTIVE_TOKEN {
+			if version_directive != nil {
+				yaml_parser_set_parser_error(parser,
+					"found duplicate %YAML directive", token.start_mark)
+				return false
+			}
+			if token.major != 1 || token.minor != 1 {
+				yaml_parser_set_parser_error(parser,
+					"found incompatible YAML document", token.start_mark)
+				return false
+			}
+			version_directive = &yaml_version_directive_t{
+				major: token.major,
+				minor: token.minor,
+			}
+		} else if token.typ == yaml_TAG_DIRECTIVE_TOKEN {
+			value := yaml_tag_directive_t{
+				handle: token.value,
+				prefix: token.prefix,
+			}
+			if !yaml_parser_append_tag_directive(parser, value, false, token.start_mark) {
+				return false
+			}
+			tag_directives = append(tag_directives, value)
+		}
+
+		skip_token(parser)
+		token = peek_token(parser)
+		if token == nil {
+			return false
+		}
+	}
+
+	for i := range default_tag_directives {
+		if !yaml_parser_append_tag_directive(parser, default_tag_directives[i], true, token.start_mark) {
+			return false
+		}
+	}
+
+	if version_directive_ref != nil {
+		*version_directive_ref = version_directive
+	}
+	if tag_directives_ref != nil {
+		*tag_directives_ref = tag_directives
+	}
+	return true
+}
+
+// Append a tag directive to the directives stack.
+func yaml_parser_append_tag_directive(parser *yaml_parser_t, value yaml_tag_directive_t, allow_duplicates bool, mark yaml_mark_t) bool {
+	for i := range parser.tag_directives {
+		if bytes.Equal(value.handle, parser.tag_directives[i].handle) {
+			if allow_duplicates {
+				return true
+			}
+			return yaml_parser_set_parser_error(parser, "found duplicate %TAG directive", mark)
+		}
+	}
+
+	// [Go] I suspect the copy is unnecessary. This was likely done
+	// because there was no way to track ownership of the data.
+	value_copy := yaml_tag_directive_t{
+		handle: make([]byte, len(value.handle)),
+		prefix: make([]byte, len(value.prefix)),
+	}
+	copy(value_copy.handle, value.handle)
+	copy(value_copy.prefix, value.prefix)
+	parser.tag_directives = append(parser.tag_directives, value_copy)
+	return true
+}
diff --git a/vendor/gopkg.in/yaml.v3/readerc.go b/vendor/gopkg.in/yaml.v3/readerc.go
new file mode 100644
index 000000000000..b7de0a89c462
--- /dev/null
+++ b/vendor/gopkg.in/yaml.v3/readerc.go
@@ -0,0 +1,434 @@
+// 
+// Copyright (c) 2011-2019 Canonical Ltd
+// Copyright (c) 2006-2010 Kirill Simonov
+// 
+// Permission is hereby granted, free of charge, to any person obtaining a copy of
+// this software and associated documentation files (the "Software"), to deal in
+// the Software without restriction, including without limitation the rights to
+// use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+// of the Software, and to permit persons to whom the Software is furnished to do
+// so, subject to the following conditions:
+// 
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+// 
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+package yaml
+
+import (
+	"io"
+)
+
+// Set the reader error and return 0.
+func yaml_parser_set_reader_error(parser *yaml_parser_t, problem string, offset int, value int) bool {
+	parser.error = yaml_READER_ERROR
+	parser.problem = problem
+	parser.problem_offset = offset
+	parser.problem_value = value
+	return false
+}
+
+// Byte order marks.
+const (
+	bom_UTF8    = "\xef\xbb\xbf"
+	bom_UTF16LE = "\xff\xfe"
+	bom_UTF16BE = "\xfe\xff"
+)
+
+// Determine the input stream encoding by checking the BOM symbol. If no BOM is
+// found, the UTF-8 encoding is assumed. Return 1 on success, 0 on failure.
+func yaml_parser_determine_encoding(parser *yaml_parser_t) bool {
+	// Ensure that we had enough bytes in the raw buffer.
+	for !parser.eof && len(parser.raw_buffer)-parser.raw_buffer_pos < 3 {
+		if !yaml_parser_update_raw_buffer(parser) {
+			return false
+		}
+	}
+
+	// Determine the encoding.
+	buf := parser.raw_buffer
+	pos := parser.raw_buffer_pos
+	avail := len(buf) - pos
+	if avail >= 2 && buf[pos] == bom_UTF16LE[0] && buf[pos+1] == bom_UTF16LE[1] {
+		parser.encoding = yaml_UTF16LE_ENCODING
+		parser.raw_buffer_pos += 2
+		parser.offset += 2
+	} else if avail >= 2 && buf[pos] == bom_UTF16BE[0] && buf[pos+1] == bom_UTF16BE[1] {
+		parser.encoding = yaml_UTF16BE_ENCODING
+		parser.raw_buffer_pos += 2
+		parser.offset += 2
+	} else if avail >= 3 && buf[pos] == bom_UTF8[0] && buf[pos+1] == bom_UTF8[1] && buf[pos+2] == bom_UTF8[2] {
+		parser.encoding = yaml_UTF8_ENCODING
+		parser.raw_buffer_pos += 3
+		parser.offset += 3
+	} else {
+		parser.encoding = yaml_UTF8_ENCODING
+	}
+	return true
+}
+
+// Update the raw buffer.
+func yaml_parser_update_raw_buffer(parser *yaml_parser_t) bool {
+	size_read := 0
+
+	// Return if the raw buffer is full.
+	if parser.raw_buffer_pos == 0 && len(parser.raw_buffer) == cap(parser.raw_buffer) {
+		return true
+	}
+
+	// Return on EOF.
+	if parser.eof {
+		return true
+	}
+
+	// Move the remaining bytes in the raw buffer to the beginning.
+	if parser.raw_buffer_pos > 0 && parser.raw_buffer_pos < len(parser.raw_buffer) {
+		copy(parser.raw_buffer, parser.raw_buffer[parser.raw_buffer_pos:])
+	}
+	parser.raw_buffer = parser.raw_buffer[:len(parser.raw_buffer)-parser.raw_buffer_pos]
+	parser.raw_buffer_pos = 0
+
+	// Call the read handler to fill the buffer.
+	size_read, err := parser.read_handler(parser, parser.raw_buffer[len(parser.raw_buffer):cap(parser.raw_buffer)])
+	parser.raw_buffer = parser.raw_buffer[:len(parser.raw_buffer)+size_read]
+	if err == io.EOF {
+		parser.eof = true
+	} else if err != nil {
+		return yaml_parser_set_reader_error(parser, "input error: "+err.Error(), parser.offset, -1)
+	}
+	return true
+}
+
+// Ensure that the buffer contains at least `length` characters.
+// Return true on success, false on failure.
+//
+// The length is supposed to be significantly less that the buffer size.
+func yaml_parser_update_buffer(parser *yaml_parser_t, length int) bool {
+	if parser.read_handler == nil {
+		panic("read handler must be set")
+	}
+
+	// [Go] This function was changed to guarantee the requested length size at EOF.
+	// The fact we need to do this is pretty awful, but the description above implies
+	// for that to be the case, and there are tests
+
+	// If the EOF flag is set and the raw buffer is empty, do nothing.
+	if parser.eof && parser.raw_buffer_pos == len(parser.raw_buffer) {
+		// [Go] ACTUALLY! Read the documentation of this function above.
+		// This is just broken. To return true, we need to have the
+		// given length in the buffer. Not doing that means every single
+		// check that calls this function to make sure the buffer has a
+		// given length is Go) panicking; or C) accessing invalid memory.
+		//return true
+	}
+
+	// Return if the buffer contains enough characters.
+	if parser.unread >= length {
+		return true
+	}
+
+	// Determine the input encoding if it is not known yet.
+	if parser.encoding == yaml_ANY_ENCODING {
+		if !yaml_parser_determine_encoding(parser) {
+			return false
+		}
+	}
+
+	// Move the unread characters to the beginning of the buffer.
+	buffer_len := len(parser.buffer)
+	if parser.buffer_pos > 0 && parser.buffer_pos < buffer_len {
+		copy(parser.buffer, parser.buffer[parser.buffer_pos:])
+		buffer_len -= parser.buffer_pos
+		parser.buffer_pos = 0
+	} else if parser.buffer_pos == buffer_len {
+		buffer_len = 0
+		parser.buffer_pos = 0
+	}
+
+	// Open the whole buffer for writing, and cut it before returning.
+	parser.buffer = parser.buffer[:cap(parser.buffer)]
+
+	// Fill the buffer until it has enough characters.
+	first := true
+	for parser.unread < length {
+
+		// Fill the raw buffer if necessary.
+		if !first || parser.raw_buffer_pos == len(parser.raw_buffer) {
+			if !yaml_parser_update_raw_buffer(parser) {
+				parser.buffer = parser.buffer[:buffer_len]
+				return false
+			}
+		}
+		first = false
+
+		// Decode the raw buffer.
+	inner:
+		for parser.raw_buffer_pos != len(parser.raw_buffer) {
+			var value rune
+			var width int
+
+			raw_unread := len(parser.raw_buffer) - parser.raw_buffer_pos
+
+			// Decode the next character.
+			switch parser.encoding {
+			case yaml_UTF8_ENCODING:
+				// Decode a UTF-8 character.  Check RFC 3629
+				// (http://www.ietf.org/rfc/rfc3629.txt) for more details.
+				//
+				// The following table (taken from the RFC) is used for
+				// decoding.
+				//
+				//    Char. number range |        UTF-8 octet sequence
+				//      (hexadecimal)    |              (binary)
+				//   --------------------+------------------------------------
+				//   0000 0000-0000 007F | 0xxxxxxx
+				//   0000 0080-0000 07FF | 110xxxxx 10xxxxxx
+				//   0000 0800-0000 FFFF | 1110xxxx 10xxxxxx 10xxxxxx
+				//   0001 0000-0010 FFFF | 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx
+				//
+				// Additionally, the characters in the range 0xD800-0xDFFF
+				// are prohibited as they are reserved for use with UTF-16
+				// surrogate pairs.
+
+				// Determine the length of the UTF-8 sequence.
+				octet := parser.raw_buffer[parser.raw_buffer_pos]
+				switch {
+				case octet&0x80 == 0x00:
+					width = 1
+				case octet&0xE0 == 0xC0:
+					width = 2
+				case octet&0xF0 == 0xE0:
+					width = 3
+				case octet&0xF8 == 0xF0:
+					width = 4
+				default:
+					// The leading octet is invalid.
+					return yaml_parser_set_reader_error(parser,
+						"invalid leading UTF-8 octet",
+						parser.offset, int(octet))
+				}
+
+				// Check if the raw buffer contains an incomplete character.
+				if width > raw_unread {
+					if parser.eof {
+						return yaml_parser_set_reader_error(parser,
+							"incomplete UTF-8 octet sequence",
+							parser.offset, -1)
+					}
+					break inner
+				}
+
+				// Decode the leading octet.
+				switch {
+				case octet&0x80 == 0x00:
+					value = rune(octet & 0x7F)
+				case octet&0xE0 == 0xC0:
+					value = rune(octet & 0x1F)
+				case octet&0xF0 == 0xE0:
+					value = rune(octet & 0x0F)
+				case octet&0xF8 == 0xF0:
+					value = rune(octet & 0x07)
+				default:
+					value = 0
+				}
+
+				// Check and decode the trailing octets.
+				for k := 1; k < width; k++ {
+					octet = parser.raw_buffer[parser.raw_buffer_pos+k]
+
+					// Check if the octet is valid.
+					if (octet & 0xC0) != 0x80 {
+						return yaml_parser_set_reader_error(parser,
+							"invalid trailing UTF-8 octet",
+							parser.offset+k, int(octet))
+					}
+
+					// Decode the octet.
+					value = (value << 6) + rune(octet&0x3F)
+				}
+
+				// Check the length of the sequence against the value.
+				switch {
+				case width == 1:
+				case width == 2 && value >= 0x80:
+				case width == 3 && value >= 0x800:
+				case width == 4 && value >= 0x10000:
+				default:
+					return yaml_parser_set_reader_error(parser,
+						"invalid length of a UTF-8 sequence",
+						parser.offset, -1)
+				}
+
+				// Check the range of the value.
+				if value >= 0xD800 && value <= 0xDFFF || value > 0x10FFFF {
+					return yaml_parser_set_reader_error(parser,
+						"invalid Unicode character",
+						parser.offset, int(value))
+				}
+
+			case yaml_UTF16LE_ENCODING, yaml_UTF16BE_ENCODING:
+				var low, high int
+				if parser.encoding == yaml_UTF16LE_ENCODING {
+					low, high = 0, 1
+				} else {
+					low, high = 1, 0
+				}
+
+				// The UTF-16 encoding is not as simple as one might
+				// naively think.  Check RFC 2781
+				// (http://www.ietf.org/rfc/rfc2781.txt).
+				//
+				// Normally, two subsequent bytes describe a Unicode
+				// character.  However a special technique (called a
+				// surrogate pair) is used for specifying character
+				// values larger than 0xFFFF.
+				//
+				// A surrogate pair consists of two pseudo-characters:
+				//      high surrogate area (0xD800-0xDBFF)
+				//      low surrogate area (0xDC00-0xDFFF)
+				//
+				// The following formulas are used for decoding
+				// and encoding characters using surrogate pairs:
+				//
+				//  U  = U' + 0x10000   (0x01 00 00 <= U <= 0x10 FF FF)
+				//  U' = yyyyyyyyyyxxxxxxxxxx   (0 <= U' <= 0x0F FF FF)
+				//  W1 = 110110yyyyyyyyyy
+				//  W2 = 110111xxxxxxxxxx
+				//
+				// where U is the character value, W1 is the high surrogate
+				// area, W2 is the low surrogate area.
+
+				// Check for incomplete UTF-16 character.
+				if raw_unread < 2 {
+					if parser.eof {
+						return yaml_parser_set_reader_error(parser,
+							"incomplete UTF-16 character",
+							parser.offset, -1)
+					}
+					break inner
+				}
+
+				// Get the character.
+				value = rune(parser.raw_buffer[parser.raw_buffer_pos+low]) +
+					(rune(parser.raw_buffer[parser.raw_buffer_pos+high]) << 8)
+
+				// Check for unexpected low surrogate area.
+				if value&0xFC00 == 0xDC00 {
+					return yaml_parser_set_reader_error(parser,
+						"unexpected low surrogate area",
+						parser.offset, int(value))
+				}
+
+				// Check for a high surrogate area.
+				if value&0xFC00 == 0xD800 {
+					width = 4
+
+					// Check for incomplete surrogate pair.
+					if raw_unread < 4 {
+						if parser.eof {
+							return yaml_parser_set_reader_error(parser,
+								"incomplete UTF-16 surrogate pair",
+								parser.offset, -1)
+						}
+						break inner
+					}
+
+					// Get the next character.
+					value2 := rune(parser.raw_buffer[parser.raw_buffer_pos+low+2]) +
+						(rune(parser.raw_buffer[parser.raw_buffer_pos+high+2]) << 8)
+
+					// Check for a low surrogate area.
+					if value2&0xFC00 != 0xDC00 {
+						return yaml_parser_set_reader_error(parser,
+							"expected low surrogate area",
+							parser.offset+2, int(value2))
+					}
+
+					// Generate the value of the surrogate pair.
+					value = 0x10000 + ((value & 0x3FF) << 10) + (value2 & 0x3FF)
+				} else {
+					width = 2
+				}
+
+			default:
+				panic("impossible")
+			}
+
+			// Check if the character is in the allowed range:
+			//      #x9 | #xA | #xD | [#x20-#x7E]               (8 bit)
+			//      | #x85 | [#xA0-#xD7FF] | [#xE000-#xFFFD]    (16 bit)
+			//      | [#x10000-#x10FFFF]                        (32 bit)
+			switch {
+			case value == 0x09:
+			case value == 0x0A:
+			case value == 0x0D:
+			case value >= 0x20 && value <= 0x7E:
+			case value == 0x85:
+			case value >= 0xA0 && value <= 0xD7FF:
+			case value >= 0xE000 && value <= 0xFFFD:
+			case value >= 0x10000 && value <= 0x10FFFF:
+			default:
+				return yaml_parser_set_reader_error(parser,
+					"control characters are not allowed",
+					parser.offset, int(value))
+			}
+
+			// Move the raw pointers.
+			parser.raw_buffer_pos += width
+			parser.offset += width
+
+			// Finally put the character into the buffer.
+			if value <= 0x7F {
+				// 0000 0000-0000 007F . 0xxxxxxx
+				parser.buffer[buffer_len+0] = byte(value)
+				buffer_len += 1
+			} else if value <= 0x7FF {
+				// 0000 0080-0000 07FF . 110xxxxx 10xxxxxx
+				parser.buffer[buffer_len+0] = byte(0xC0 + (value >> 6))
+				parser.buffer[buffer_len+1] = byte(0x80 + (value & 0x3F))
+				buffer_len += 2
+			} else if value <= 0xFFFF {
+				// 0000 0800-0000 FFFF . 1110xxxx 10xxxxxx 10xxxxxx
+				parser.buffer[buffer_len+0] = byte(0xE0 + (value >> 12))
+				parser.buffer[buffer_len+1] = byte(0x80 + ((value >> 6) & 0x3F))
+				parser.buffer[buffer_len+2] = byte(0x80 + (value & 0x3F))
+				buffer_len += 3
+			} else {
+				// 0001 0000-0010 FFFF . 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx
+				parser.buffer[buffer_len+0] = byte(0xF0 + (value >> 18))
+				parser.buffer[buffer_len+1] = byte(0x80 + ((value >> 12) & 0x3F))
+				parser.buffer[buffer_len+2] = byte(0x80 + ((value >> 6) & 0x3F))
+				parser.buffer[buffer_len+3] = byte(0x80 + (value & 0x3F))
+				buffer_len += 4
+			}
+
+			parser.unread++
+		}
+
+		// On EOF, put NUL into the buffer and return.
+		if parser.eof {
+			parser.buffer[buffer_len] = 0
+			buffer_len++
+			parser.unread++
+			break
+		}
+	}
+	// [Go] Read the documentation of this function above. To return true,
+	// we need to have the given length in the buffer. Not doing that means
+	// every single check that calls this function to make sure the buffer
+	// has a given length is Go) panicking; or C) accessing invalid memory.
+	// This happens here due to the EOF above breaking early.
+	for buffer_len < length {
+		parser.buffer[buffer_len] = 0
+		buffer_len++
+	}
+	parser.buffer = parser.buffer[:buffer_len]
+	return true
+}
diff --git a/vendor/gopkg.in/yaml.v3/resolve.go b/vendor/gopkg.in/yaml.v3/resolve.go
new file mode 100644
index 000000000000..64ae888057a5
--- /dev/null
+++ b/vendor/gopkg.in/yaml.v3/resolve.go
@@ -0,0 +1,326 @@
+//
+// Copyright (c) 2011-2019 Canonical Ltd
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package yaml
+
+import (
+	"encoding/base64"
+	"math"
+	"regexp"
+	"strconv"
+	"strings"
+	"time"
+)
+
+type resolveMapItem struct {
+	value interface{}
+	tag   string
+}
+
+var resolveTable = make([]byte, 256)
+var resolveMap = make(map[string]resolveMapItem)
+
+func init() {
+	t := resolveTable
+	t[int('+')] = 'S' // Sign
+	t[int('-')] = 'S'
+	for _, c := range "0123456789" {
+		t[int(c)] = 'D' // Digit
+	}
+	for _, c := range "yYnNtTfFoO~" {
+		t[int(c)] = 'M' // In map
+	}
+	t[int('.')] = '.' // Float (potentially in map)
+
+	var resolveMapList = []struct {
+		v   interface{}
+		tag string
+		l   []string
+	}{
+		{true, boolTag, []string{"true", "True", "TRUE"}},
+		{false, boolTag, []string{"false", "False", "FALSE"}},
+		{nil, nullTag, []string{"", "~", "null", "Null", "NULL"}},
+		{math.NaN(), floatTag, []string{".nan", ".NaN", ".NAN"}},
+		{math.Inf(+1), floatTag, []string{".inf", ".Inf", ".INF"}},
+		{math.Inf(+1), floatTag, []string{"+.inf", "+.Inf", "+.INF"}},
+		{math.Inf(-1), floatTag, []string{"-.inf", "-.Inf", "-.INF"}},
+		{"<<", mergeTag, []string{"<<"}},
+	}
+
+	m := resolveMap
+	for _, item := range resolveMapList {
+		for _, s := range item.l {
+			m[s] = resolveMapItem{item.v, item.tag}
+		}
+	}
+}
+
+const (
+	nullTag      = "!!null"
+	boolTag      = "!!bool"
+	strTag       = "!!str"
+	intTag       = "!!int"
+	floatTag     = "!!float"
+	timestampTag = "!!timestamp"
+	seqTag       = "!!seq"
+	mapTag       = "!!map"
+	binaryTag    = "!!binary"
+	mergeTag     = "!!merge"
+)
+
+var longTags = make(map[string]string)
+var shortTags = make(map[string]string)
+
+func init() {
+	for _, stag := range []string{nullTag, boolTag, strTag, intTag, floatTag, timestampTag, seqTag, mapTag, binaryTag, mergeTag} {
+		ltag := longTag(stag)
+		longTags[stag] = ltag
+		shortTags[ltag] = stag
+	}
+}
+
+const longTagPrefix = "tag:yaml.org,2002:"
+
+func shortTag(tag string) string {
+	if strings.HasPrefix(tag, longTagPrefix) {
+		if stag, ok := shortTags[tag]; ok {
+			return stag
+		}
+		return "!!" + tag[len(longTagPrefix):]
+	}
+	return tag
+}
+
+func longTag(tag string) string {
+	if strings.HasPrefix(tag, "!!") {
+		if ltag, ok := longTags[tag]; ok {
+			return ltag
+		}
+		return longTagPrefix + tag[2:]
+	}
+	return tag
+}
+
+func resolvableTag(tag string) bool {
+	switch tag {
+	case "", strTag, boolTag, intTag, floatTag, nullTag, timestampTag:
+		return true
+	}
+	return false
+}
+
+var yamlStyleFloat = regexp.MustCompile(`^[-+]?(\.[0-9]+|[0-9]+(\.[0-9]*)?)([eE][-+]?[0-9]+)?$`)
+
+func resolve(tag string, in string) (rtag string, out interface{}) {
+	tag = shortTag(tag)
+	if !resolvableTag(tag) {
+		return tag, in
+	}
+
+	defer func() {
+		switch tag {
+		case "", rtag, strTag, binaryTag:
+			return
+		case floatTag:
+			if rtag == intTag {
+				switch v := out.(type) {
+				case int64:
+					rtag = floatTag
+					out = float64(v)
+					return
+				case int:
+					rtag = floatTag
+					out = float64(v)
+					return
+				}
+			}
+		}
+		failf("cannot decode %s `%s` as a %s", shortTag(rtag), in, shortTag(tag))
+	}()
+
+	// Any data is accepted as a !!str or !!binary.
+	// Otherwise, the prefix is enough of a hint about what it might be.
+	hint := byte('N')
+	if in != "" {
+		hint = resolveTable[in[0]]
+	}
+	if hint != 0 && tag != strTag && tag != binaryTag {
+		// Handle things we can lookup in a map.
+		if item, ok := resolveMap[in]; ok {
+			return item.tag, item.value
+		}
+
+		// Base 60 floats are a bad idea, were dropped in YAML 1.2, and
+		// are purposefully unsupported here. They're still quoted on
+		// the way out for compatibility with other parser, though.
+
+		switch hint {
+		case 'M':
+			// We've already checked the map above.
+
+		case '.':
+			// Not in the map, so maybe a normal float.
+			floatv, err := strconv.ParseFloat(in, 64)
+			if err == nil {
+				return floatTag, floatv
+			}
+
+		case 'D', 'S':
+			// Int, float, or timestamp.
+			// Only try values as a timestamp if the value is unquoted or there's an explicit
+			// !!timestamp tag.
+			if tag == "" || tag == timestampTag {
+				t, ok := parseTimestamp(in)
+				if ok {
+					return timestampTag, t
+				}
+			}
+
+			plain := strings.Replace(in, "_", "", -1)
+			intv, err := strconv.ParseInt(plain, 0, 64)
+			if err == nil {
+				if intv == int64(int(intv)) {
+					return intTag, int(intv)
+				} else {
+					return intTag, intv
+				}
+			}
+			uintv, err := strconv.ParseUint(plain, 0, 64)
+			if err == nil {
+				return intTag, uintv
+			}
+			if yamlStyleFloat.MatchString(plain) {
+				floatv, err := strconv.ParseFloat(plain, 64)
+				if err == nil {
+					return floatTag, floatv
+				}
+			}
+			if strings.HasPrefix(plain, "0b") {
+				intv, err := strconv.ParseInt(plain[2:], 2, 64)
+				if err == nil {
+					if intv == int64(int(intv)) {
+						return intTag, int(intv)
+					} else {
+						return intTag, intv
+					}
+				}
+				uintv, err := strconv.ParseUint(plain[2:], 2, 64)
+				if err == nil {
+					return intTag, uintv
+				}
+			} else if strings.HasPrefix(plain, "-0b") {
+				intv, err := strconv.ParseInt("-"+plain[3:], 2, 64)
+				if err == nil {
+					if true || intv == int64(int(intv)) {
+						return intTag, int(intv)
+					} else {
+						return intTag, intv
+					}
+				}
+			}
+			// Octals as introduced in version 1.2 of the spec.
+			// Octals from the 1.1 spec, spelled as 0777, are still
+			// decoded by default in v3 as well for compatibility.
+			// May be dropped in v4 depending on how usage evolves.
+			if strings.HasPrefix(plain, "0o") {
+				intv, err := strconv.ParseInt(plain[2:], 8, 64)
+				if err == nil {
+					if intv == int64(int(intv)) {
+						return intTag, int(intv)
+					} else {
+						return intTag, intv
+					}
+				}
+				uintv, err := strconv.ParseUint(plain[2:], 8, 64)
+				if err == nil {
+					return intTag, uintv
+				}
+			} else if strings.HasPrefix(plain, "-0o") {
+				intv, err := strconv.ParseInt("-"+plain[3:], 8, 64)
+				if err == nil {
+					if true || intv == int64(int(intv)) {
+						return intTag, int(intv)
+					} else {
+						return intTag, intv
+					}
+				}
+			}
+		default:
+			panic("internal error: missing handler for resolver table: " + string(rune(hint)) + " (with " + in + ")")
+		}
+	}
+	return strTag, in
+}
+
+// encodeBase64 encodes s as base64 that is broken up into multiple lines
+// as appropriate for the resulting length.
+func encodeBase64(s string) string {
+	const lineLen = 70
+	encLen := base64.StdEncoding.EncodedLen(len(s))
+	lines := encLen/lineLen + 1
+	buf := make([]byte, encLen*2+lines)
+	in := buf[0:encLen]
+	out := buf[encLen:]
+	base64.StdEncoding.Encode(in, []byte(s))
+	k := 0
+	for i := 0; i < len(in); i += lineLen {
+		j := i + lineLen
+		if j > len(in) {
+			j = len(in)
+		}
+		k += copy(out[k:], in[i:j])
+		if lines > 1 {
+			out[k] = '\n'
+			k++
+		}
+	}
+	return string(out[:k])
+}
+
+// This is a subset of the formats allowed by the regular expression
+// defined at http://yaml.org/type/timestamp.html.
+var allowedTimestampFormats = []string{
+	"2006-1-2T15:4:5.999999999Z07:00", // RCF3339Nano with short date fields.
+	"2006-1-2t15:4:5.999999999Z07:00", // RFC3339Nano with short date fields and lower-case "t".
+	"2006-1-2 15:4:5.999999999",       // space separated with no time zone
+	"2006-1-2",                        // date only
+	// Notable exception: time.Parse cannot handle: "2001-12-14 21:59:43.10 -5"
+	// from the set of examples.
+}
+
+// parseTimestamp parses s as a timestamp string and
+// returns the timestamp and reports whether it succeeded.
+// Timestamp formats are defined at http://yaml.org/type/timestamp.html
+func parseTimestamp(s string) (time.Time, bool) {
+	// TODO write code to check all the formats supported by
+	// http://yaml.org/type/timestamp.html instead of using time.Parse.
+
+	// Quick check: all date formats start with YYYY-.
+	i := 0
+	for ; i < len(s); i++ {
+		if c := s[i]; c < '0' || c > '9' {
+			break
+		}
+	}
+	if i != 4 || i == len(s) || s[i] != '-' {
+		return time.Time{}, false
+	}
+	for _, format := range allowedTimestampFormats {
+		if t, err := time.Parse(format, s); err == nil {
+			return t, true
+		}
+	}
+	return time.Time{}, false
+}
diff --git a/vendor/gopkg.in/yaml.v3/scannerc.go b/vendor/gopkg.in/yaml.v3/scannerc.go
new file mode 100644
index 000000000000..ca0070108f4e
--- /dev/null
+++ b/vendor/gopkg.in/yaml.v3/scannerc.go
@@ -0,0 +1,3038 @@
+//
+// Copyright (c) 2011-2019 Canonical Ltd
+// Copyright (c) 2006-2010 Kirill Simonov
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy of
+// this software and associated documentation files (the "Software"), to deal in
+// the Software without restriction, including without limitation the rights to
+// use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+// of the Software, and to permit persons to whom the Software is furnished to do
+// so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+package yaml
+
+import (
+	"bytes"
+	"fmt"
+)
+
+// Introduction
+// ************
+//
+// The following notes assume that you are familiar with the YAML specification
+// (http://yaml.org/spec/1.2/spec.html).  We mostly follow it, although in
+// some cases we are less restrictive that it requires.
+//
+// The process of transforming a YAML stream into a sequence of events is
+// divided on two steps: Scanning and Parsing.
+//
+// The Scanner transforms the input stream into a sequence of tokens, while the
+// parser transform the sequence of tokens produced by the Scanner into a
+// sequence of parsing events.
+//
+// The Scanner is rather clever and complicated. The Parser, on the contrary,
+// is a straightforward implementation of a recursive-descendant parser (or,
+// LL(1) parser, as it is usually called).
+//
+// Actually there are two issues of Scanning that might be called "clever", the
+// rest is quite straightforward.  The issues are "block collection start" and
+// "simple keys".  Both issues are explained below in details.
+//
+// Here the Scanning step is explained and implemented.  We start with the list
+// of all the tokens produced by the Scanner together with short descriptions.
+//
+// Now, tokens:
+//
+//      STREAM-START(encoding)          # The stream start.
+//      STREAM-END                      # The stream end.
+//      VERSION-DIRECTIVE(major,minor)  # The '%YAML' directive.
+//      TAG-DIRECTIVE(handle,prefix)    # The '%TAG' directive.
+//      DOCUMENT-START                  # '---'
+//      DOCUMENT-END                    # '...'
+//      BLOCK-SEQUENCE-START            # Indentation increase denoting a block
+//      BLOCK-MAPPING-START             # sequence or a block mapping.
+//      BLOCK-END                       # Indentation decrease.
+//      FLOW-SEQUENCE-START             # '['
+//      FLOW-SEQUENCE-END               # ']'
+//      BLOCK-SEQUENCE-START            # '{'
+//      BLOCK-SEQUENCE-END              # '}'
+//      BLOCK-ENTRY                     # '-'
+//      FLOW-ENTRY                      # ','
+//      KEY                             # '?' or nothing (simple keys).
+//      VALUE                           # ':'
+//      ALIAS(anchor)                   # '*anchor'
+//      ANCHOR(anchor)                  # '&anchor'
+//      TAG(handle,suffix)              # '!handle!suffix'
+//      SCALAR(value,style)             # A scalar.
+//
+// The following two tokens are "virtual" tokens denoting the beginning and the
+// end of the stream:
+//
+//      STREAM-START(encoding)
+//      STREAM-END
+//
+// We pass the information about the input stream encoding with the
+// STREAM-START token.
+//
+// The next two tokens are responsible for tags:
+//
+//      VERSION-DIRECTIVE(major,minor)
+//      TAG-DIRECTIVE(handle,prefix)
+//
+// Example:
+//
+//      %YAML   1.1
+//      %TAG    !   !foo
+//      %TAG    !yaml!  tag:yaml.org,2002:
+//      ---
+//
+// The correspoding sequence of tokens:
+//
+//      STREAM-START(utf-8)
+//      VERSION-DIRECTIVE(1,1)
+//      TAG-DIRECTIVE("!","!foo")
+//      TAG-DIRECTIVE("!yaml","tag:yaml.org,2002:")
+//      DOCUMENT-START
+//      STREAM-END
+//
+// Note that the VERSION-DIRECTIVE and TAG-DIRECTIVE tokens occupy a whole
+// line.
+//
+// The document start and end indicators are represented by:
+//
+//      DOCUMENT-START
+//      DOCUMENT-END
+//
+// Note that if a YAML stream contains an implicit document (without '---'
+// and '...' indicators), no DOCUMENT-START and DOCUMENT-END tokens will be
+// produced.
+//
+// In the following examples, we present whole documents together with the
+// produced tokens.
+//
+//      1. An implicit document:
+//
+//          'a scalar'
+//
+//      Tokens:
+//
+//          STREAM-START(utf-8)
+//          SCALAR("a scalar",single-quoted)
+//          STREAM-END
+//
+//      2. An explicit document:
+//
+//          ---
+//          'a scalar'
+//          ...
+//
+//      Tokens:
+//
+//          STREAM-START(utf-8)
+//          DOCUMENT-START
+//          SCALAR("a scalar",single-quoted)
+//          DOCUMENT-END
+//          STREAM-END
+//
+//      3. Several documents in a stream:
+//
+//          'a scalar'
+//          ---
+//          'another scalar'
+//          ---
+//          'yet another scalar'
+//
+//      Tokens:
+//
+//          STREAM-START(utf-8)
+//          SCALAR("a scalar",single-quoted)
+//          DOCUMENT-START
+//          SCALAR("another scalar",single-quoted)
+//          DOCUMENT-START
+//          SCALAR("yet another scalar",single-quoted)
+//          STREAM-END
+//
+// We have already introduced the SCALAR token above.  The following tokens are
+// used to describe aliases, anchors, tag, and scalars:
+//
+//      ALIAS(anchor)
+//      ANCHOR(anchor)
+//      TAG(handle,suffix)
+//      SCALAR(value,style)
+//
+// The following series of examples illustrate the usage of these tokens:
+//
+//      1. A recursive sequence:
+//
+//          &A [ *A ]
+//
+//      Tokens:
+//
+//          STREAM-START(utf-8)
+//          ANCHOR("A")
+//          FLOW-SEQUENCE-START
+//          ALIAS("A")
+//          FLOW-SEQUENCE-END
+//          STREAM-END
+//
+//      2. A tagged scalar:
+//
+//          !!float "3.14"  # A good approximation.
+//
+//      Tokens:
+//
+//          STREAM-START(utf-8)
+//          TAG("!!","float")
+//          SCALAR("3.14",double-quoted)
+//          STREAM-END
+//
+//      3. Various scalar styles:
+//
+//          --- # Implicit empty plain scalars do not produce tokens.
+//          --- a plain scalar
+//          --- 'a single-quoted scalar'
+//          --- "a double-quoted scalar"
+//          --- |-
+//            a literal scalar
+//          --- >-
+//            a folded
+//            scalar
+//
+//      Tokens:
+//
+//          STREAM-START(utf-8)
+//          DOCUMENT-START
+//          DOCUMENT-START
+//          SCALAR("a plain scalar",plain)
+//          DOCUMENT-START
+//          SCALAR("a single-quoted scalar",single-quoted)
+//          DOCUMENT-START
+//          SCALAR("a double-quoted scalar",double-quoted)
+//          DOCUMENT-START
+//          SCALAR("a literal scalar",literal)
+//          DOCUMENT-START
+//          SCALAR("a folded scalar",folded)
+//          STREAM-END
+//
+// Now it's time to review collection-related tokens. We will start with
+// flow collections:
+//
+//      FLOW-SEQUENCE-START
+//      FLOW-SEQUENCE-END
+//      FLOW-MAPPING-START
+//      FLOW-MAPPING-END
+//      FLOW-ENTRY
+//      KEY
+//      VALUE
+//
+// The tokens FLOW-SEQUENCE-START, FLOW-SEQUENCE-END, FLOW-MAPPING-START, and
+// FLOW-MAPPING-END represent the indicators '[', ']', '{', and '}'
+// correspondingly.  FLOW-ENTRY represent the ',' indicator.  Finally the
+// indicators '?' and ':', which are used for denoting mapping keys and values,
+// are represented by the KEY and VALUE tokens.
+//
+// The following examples show flow collections:
+//
+//      1. A flow sequence:
+//
+//          [item 1, item 2, item 3]
+//
+//      Tokens:
+//
+//          STREAM-START(utf-8)
+//          FLOW-SEQUENCE-START
+//          SCALAR("item 1",plain)
+//          FLOW-ENTRY
+//          SCALAR("item 2",plain)
+//          FLOW-ENTRY
+//          SCALAR("item 3",plain)
+//          FLOW-SEQUENCE-END
+//          STREAM-END
+//
+//      2. A flow mapping:
+//
+//          {
+//              a simple key: a value,  # Note that the KEY token is produced.
+//              ? a complex key: another value,
+//          }
+//
+//      Tokens:
+//
+//          STREAM-START(utf-8)
+//          FLOW-MAPPING-START
+//          KEY
+//          SCALAR("a simple key",plain)
+//          VALUE
+//          SCALAR("a value",plain)
+//          FLOW-ENTRY
+//          KEY
+//          SCALAR("a complex key",plain)
+//          VALUE
+//          SCALAR("another value",plain)
+//          FLOW-ENTRY
+//          FLOW-MAPPING-END
+//          STREAM-END
+//
+// A simple key is a key which is not denoted by the '?' indicator.  Note that
+// the Scanner still produce the KEY token whenever it encounters a simple key.
+//
+// For scanning block collections, the following tokens are used (note that we
+// repeat KEY and VALUE here):
+//
+//      BLOCK-SEQUENCE-START
+//      BLOCK-MAPPING-START
+//      BLOCK-END
+//      BLOCK-ENTRY
+//      KEY
+//      VALUE
+//
+// The tokens BLOCK-SEQUENCE-START and BLOCK-MAPPING-START denote indentation
+// increase that precedes a block collection (cf. the INDENT token in Python).
+// The token BLOCK-END denote indentation decrease that ends a block collection
+// (cf. the DEDENT token in Python).  However YAML has some syntax pecularities
+// that makes detections of these tokens more complex.
+//
+// The tokens BLOCK-ENTRY, KEY, and VALUE are used to represent the indicators
+// '-', '?', and ':' correspondingly.
+//
+// The following examples show how the tokens BLOCK-SEQUENCE-START,
+// BLOCK-MAPPING-START, and BLOCK-END are emitted by the Scanner:
+//
+//      1. Block sequences:
+//
+//          - item 1
+//          - item 2
+//          -
+//            - item 3.1
+//            - item 3.2
+//          -
+//            key 1: value 1
+//            key 2: value 2
+//
+//      Tokens:
+//
+//          STREAM-START(utf-8)
+//          BLOCK-SEQUENCE-START
+//          BLOCK-ENTRY
+//          SCALAR("item 1",plain)
+//          BLOCK-ENTRY
+//          SCALAR("item 2",plain)
+//          BLOCK-ENTRY
+//          BLOCK-SEQUENCE-START
+//          BLOCK-ENTRY
+//          SCALAR("item 3.1",plain)
+//          BLOCK-ENTRY
+//          SCALAR("item 3.2",plain)
+//          BLOCK-END
+//          BLOCK-ENTRY
+//          BLOCK-MAPPING-START
+//          KEY
+//          SCALAR("key 1",plain)
+//          VALUE
+//          SCALAR("value 1",plain)
+//          KEY
+//          SCALAR("key 2",plain)
+//          VALUE
+//          SCALAR("value 2",plain)
+//          BLOCK-END
+//          BLOCK-END
+//          STREAM-END
+//
+//      2. Block mappings:
+//
+//          a simple key: a value   # The KEY token is produced here.
+//          ? a complex key
+//          : another value
+//          a mapping:
+//            key 1: value 1
+//            key 2: value 2
+//          a sequence:
+//            - item 1
+//            - item 2
+//
+//      Tokens:
+//
+//          STREAM-START(utf-8)
+//          BLOCK-MAPPING-START
+//          KEY
+//          SCALAR("a simple key",plain)
+//          VALUE
+//          SCALAR("a value",plain)
+//          KEY
+//          SCALAR("a complex key",plain)
+//          VALUE
+//          SCALAR("another value",plain)
+//          KEY
+//          SCALAR("a mapping",plain)
+//          BLOCK-MAPPING-START
+//          KEY
+//          SCALAR("key 1",plain)
+//          VALUE
+//          SCALAR("value 1",plain)
+//          KEY
+//          SCALAR("key 2",plain)
+//          VALUE
+//          SCALAR("value 2",plain)
+//          BLOCK-END
+//          KEY
+//          SCALAR("a sequence",plain)
+//          VALUE
+//          BLOCK-SEQUENCE-START
+//          BLOCK-ENTRY
+//          SCALAR("item 1",plain)
+//          BLOCK-ENTRY
+//          SCALAR("item 2",plain)
+//          BLOCK-END
+//          BLOCK-END
+//          STREAM-END
+//
+// YAML does not always require to start a new block collection from a new
+// line.  If the current line contains only '-', '?', and ':' indicators, a new
+// block collection may start at the current line.  The following examples
+// illustrate this case:
+//
+//      1. Collections in a sequence:
+//
+//          - - item 1
+//            - item 2
+//          - key 1: value 1
+//            key 2: value 2
+//          - ? complex key
+//            : complex value
+//
+//      Tokens:
+//
+//          STREAM-START(utf-8)
+//          BLOCK-SEQUENCE-START
+//          BLOCK-ENTRY
+//          BLOCK-SEQUENCE-START
+//          BLOCK-ENTRY
+//          SCALAR("item 1",plain)
+//          BLOCK-ENTRY
+//          SCALAR("item 2",plain)
+//          BLOCK-END
+//          BLOCK-ENTRY
+//          BLOCK-MAPPING-START
+//          KEY
+//          SCALAR("key 1",plain)
+//          VALUE
+//          SCALAR("value 1",plain)
+//          KEY
+//          SCALAR("key 2",plain)
+//          VALUE
+//          SCALAR("value 2",plain)
+//          BLOCK-END
+//          BLOCK-ENTRY
+//          BLOCK-MAPPING-START
+//          KEY
+//          SCALAR("complex key")
+//          VALUE
+//          SCALAR("complex value")
+//          BLOCK-END
+//          BLOCK-END
+//          STREAM-END
+//
+//      2. Collections in a mapping:
+//
+//          ? a sequence
+//          : - item 1
+//            - item 2
+//          ? a mapping
+//          : key 1: value 1
+//            key 2: value 2
+//
+//      Tokens:
+//
+//          STREAM-START(utf-8)
+//          BLOCK-MAPPING-START
+//          KEY
+//          SCALAR("a sequence",plain)
+//          VALUE
+//          BLOCK-SEQUENCE-START
+//          BLOCK-ENTRY
+//          SCALAR("item 1",plain)
+//          BLOCK-ENTRY
+//          SCALAR("item 2",plain)
+//          BLOCK-END
+//          KEY
+//          SCALAR("a mapping",plain)
+//          VALUE
+//          BLOCK-MAPPING-START
+//          KEY
+//          SCALAR("key 1",plain)
+//          VALUE
+//          SCALAR("value 1",plain)
+//          KEY
+//          SCALAR("key 2",plain)
+//          VALUE
+//          SCALAR("value 2",plain)
+//          BLOCK-END
+//          BLOCK-END
+//          STREAM-END
+//
+// YAML also permits non-indented sequences if they are included into a block
+// mapping.  In this case, the token BLOCK-SEQUENCE-START is not produced:
+//
+//      key:
+//      - item 1    # BLOCK-SEQUENCE-START is NOT produced here.
+//      - item 2
+//
+// Tokens:
+//
+//      STREAM-START(utf-8)
+//      BLOCK-MAPPING-START
+//      KEY
+//      SCALAR("key",plain)
+//      VALUE
+//      BLOCK-ENTRY
+//      SCALAR("item 1",plain)
+//      BLOCK-ENTRY
+//      SCALAR("item 2",plain)
+//      BLOCK-END
+//
+
+// Ensure that the buffer contains the required number of characters.
+// Return true on success, false on failure (reader error or memory error).
+func cache(parser *yaml_parser_t, length int) bool {
+	// [Go] This was inlined: !cache(A, B) -> unread < B && !update(A, B)
+	return parser.unread >= length || yaml_parser_update_buffer(parser, length)
+}
+
+// Advance the buffer pointer.
+func skip(parser *yaml_parser_t) {
+	if !is_blank(parser.buffer, parser.buffer_pos) {
+		parser.newlines = 0
+	}
+	parser.mark.index++
+	parser.mark.column++
+	parser.unread--
+	parser.buffer_pos += width(parser.buffer[parser.buffer_pos])
+}
+
+func skip_line(parser *yaml_parser_t) {
+	if is_crlf(parser.buffer, parser.buffer_pos) {
+		parser.mark.index += 2
+		parser.mark.column = 0
+		parser.mark.line++
+		parser.unread -= 2
+		parser.buffer_pos += 2
+		parser.newlines++
+	} else if is_break(parser.buffer, parser.buffer_pos) {
+		parser.mark.index++
+		parser.mark.column = 0
+		parser.mark.line++
+		parser.unread--
+		parser.buffer_pos += width(parser.buffer[parser.buffer_pos])
+		parser.newlines++
+	}
+}
+
+// Copy a character to a string buffer and advance pointers.
+func read(parser *yaml_parser_t, s []byte) []byte {
+	if !is_blank(parser.buffer, parser.buffer_pos) {
+		parser.newlines = 0
+	}
+	w := width(parser.buffer[parser.buffer_pos])
+	if w == 0 {
+		panic("invalid character sequence")
+	}
+	if len(s) == 0 {
+		s = make([]byte, 0, 32)
+	}
+	if w == 1 && len(s)+w <= cap(s) {
+		s = s[:len(s)+1]
+		s[len(s)-1] = parser.buffer[parser.buffer_pos]
+		parser.buffer_pos++
+	} else {
+		s = append(s, parser.buffer[parser.buffer_pos:parser.buffer_pos+w]...)
+		parser.buffer_pos += w
+	}
+	parser.mark.index++
+	parser.mark.column++
+	parser.unread--
+	return s
+}
+
+// Copy a line break character to a string buffer and advance pointers.
+func read_line(parser *yaml_parser_t, s []byte) []byte {
+	buf := parser.buffer
+	pos := parser.buffer_pos
+	switch {
+	case buf[pos] == '\r' && buf[pos+1] == '\n':
+		// CR LF . LF
+		s = append(s, '\n')
+		parser.buffer_pos += 2
+		parser.mark.index++
+		parser.unread--
+	case buf[pos] == '\r' || buf[pos] == '\n':
+		// CR|LF . LF
+		s = append(s, '\n')
+		parser.buffer_pos += 1
+	case buf[pos] == '\xC2' && buf[pos+1] == '\x85':
+		// NEL . LF
+		s = append(s, '\n')
+		parser.buffer_pos += 2
+	case buf[pos] == '\xE2' && buf[pos+1] == '\x80' && (buf[pos+2] == '\xA8' || buf[pos+2] == '\xA9'):
+		// LS|PS . LS|PS
+		s = append(s, buf[parser.buffer_pos:pos+3]...)
+		parser.buffer_pos += 3
+	default:
+		return s
+	}
+	parser.mark.index++
+	parser.mark.column = 0
+	parser.mark.line++
+	parser.unread--
+	parser.newlines++
+	return s
+}
+
+// Get the next token.
+func yaml_parser_scan(parser *yaml_parser_t, token *yaml_token_t) bool {
+	// Erase the token object.
+	*token = yaml_token_t{} // [Go] Is this necessary?
+
+	// No tokens after STREAM-END or error.
+	if parser.stream_end_produced || parser.error != yaml_NO_ERROR {
+		return true
+	}
+
+	// Ensure that the tokens queue contains enough tokens.
+	if !parser.token_available {
+		if !yaml_parser_fetch_more_tokens(parser) {
+			return false
+		}
+	}
+
+	// Fetch the next token from the queue.
+	*token = parser.tokens[parser.tokens_head]
+	parser.tokens_head++
+	parser.tokens_parsed++
+	parser.token_available = false
+
+	if token.typ == yaml_STREAM_END_TOKEN {
+		parser.stream_end_produced = true
+	}
+	return true
+}
+
+// Set the scanner error and return false.
+func yaml_parser_set_scanner_error(parser *yaml_parser_t, context string, context_mark yaml_mark_t, problem string) bool {
+	parser.error = yaml_SCANNER_ERROR
+	parser.context = context
+	parser.context_mark = context_mark
+	parser.problem = problem
+	parser.problem_mark = parser.mark
+	return false
+}
+
+func yaml_parser_set_scanner_tag_error(parser *yaml_parser_t, directive bool, context_mark yaml_mark_t, problem string) bool {
+	context := "while parsing a tag"
+	if directive {
+		context = "while parsing a %TAG directive"
+	}
+	return yaml_parser_set_scanner_error(parser, context, context_mark, problem)
+}
+
+func trace(args ...interface{}) func() {
+	pargs := append([]interface{}{"+++"}, args...)
+	fmt.Println(pargs...)
+	pargs = append([]interface{}{"---"}, args...)
+	return func() { fmt.Println(pargs...) }
+}
+
+// Ensure that the tokens queue contains at least one token which can be
+// returned to the Parser.
+func yaml_parser_fetch_more_tokens(parser *yaml_parser_t) bool {
+	// While we need more tokens to fetch, do it.
+	for {
+		// [Go] The comment parsing logic requires a lookahead of two tokens
+		// so that foot comments may be parsed in time of associating them
+		// with the tokens that are parsed before them, and also for line
+		// comments to be transformed into head comments in some edge cases.
+		if parser.tokens_head < len(parser.tokens)-2 {
+			// If a potential simple key is at the head position, we need to fetch
+			// the next token to disambiguate it.
+			head_tok_idx, ok := parser.simple_keys_by_tok[parser.tokens_parsed]
+			if !ok {
+				break
+			} else if valid, ok := yaml_simple_key_is_valid(parser, &parser.simple_keys[head_tok_idx]); !ok {
+				return false
+			} else if !valid {
+				break
+			}
+		}
+		// Fetch the next token.
+		if !yaml_parser_fetch_next_token(parser) {
+			return false
+		}
+	}
+
+	parser.token_available = true
+	return true
+}
+
+// The dispatcher for token fetchers.
+func yaml_parser_fetch_next_token(parser *yaml_parser_t) (ok bool) {
+	// Ensure that the buffer is initialized.
+	if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+		return false
+	}
+
+	// Check if we just started scanning.  Fetch STREAM-START then.
+	if !parser.stream_start_produced {
+		return yaml_parser_fetch_stream_start(parser)
+	}
+
+	scan_mark := parser.mark
+
+	// Eat whitespaces and comments until we reach the next token.
+	if !yaml_parser_scan_to_next_token(parser) {
+		return false
+	}
+
+	// [Go] While unrolling indents, transform the head comments of prior
+	// indentation levels observed after scan_start into foot comments at
+	// the respective indexes.
+
+	// Check the indentation level against the current column.
+	if !yaml_parser_unroll_indent(parser, parser.mark.column, scan_mark) {
+		return false
+	}
+
+	// Ensure that the buffer contains at least 4 characters.  4 is the length
+	// of the longest indicators ('--- ' and '... ').
+	if parser.unread < 4 && !yaml_parser_update_buffer(parser, 4) {
+		return false
+	}
+
+	// Is it the end of the stream?
+	if is_z(parser.buffer, parser.buffer_pos) {
+		return yaml_parser_fetch_stream_end(parser)
+	}
+
+	// Is it a directive?
+	if parser.mark.column == 0 && parser.buffer[parser.buffer_pos] == '%' {
+		return yaml_parser_fetch_directive(parser)
+	}
+
+	buf := parser.buffer
+	pos := parser.buffer_pos
+
+	// Is it the document start indicator?
+	if parser.mark.column == 0 && buf[pos] == '-' && buf[pos+1] == '-' && buf[pos+2] == '-' && is_blankz(buf, pos+3) {
+		return yaml_parser_fetch_document_indicator(parser, yaml_DOCUMENT_START_TOKEN)
+	}
+
+	// Is it the document end indicator?
+	if parser.mark.column == 0 && buf[pos] == '.' && buf[pos+1] == '.' && buf[pos+2] == '.' && is_blankz(buf, pos+3) {
+		return yaml_parser_fetch_document_indicator(parser, yaml_DOCUMENT_END_TOKEN)
+	}
+
+	comment_mark := parser.mark
+	if len(parser.tokens) > 0 && (parser.flow_level == 0 && buf[pos] == ':' || parser.flow_level > 0 && buf[pos] == ',') {
+		// Associate any following comments with the prior token.
+		comment_mark = parser.tokens[len(parser.tokens)-1].start_mark
+	}
+	defer func() {
+		if !ok {
+			return
+		}
+		if len(parser.tokens) > 0 && parser.tokens[len(parser.tokens)-1].typ == yaml_BLOCK_ENTRY_TOKEN {
+			// Sequence indicators alone have no line comments. It becomes
+			// a head comment for whatever follows.
+			return
+		}
+		if !yaml_parser_scan_line_comment(parser, comment_mark) {
+			ok = false
+			return
+		}
+	}()
+
+	// Is it the flow sequence start indicator?
+	if buf[pos] == '[' {
+		return yaml_parser_fetch_flow_collection_start(parser, yaml_FLOW_SEQUENCE_START_TOKEN)
+	}
+
+	// Is it the flow mapping start indicator?
+	if parser.buffer[parser.buffer_pos] == '{' {
+		return yaml_parser_fetch_flow_collection_start(parser, yaml_FLOW_MAPPING_START_TOKEN)
+	}
+
+	// Is it the flow sequence end indicator?
+	if parser.buffer[parser.buffer_pos] == ']' {
+		return yaml_parser_fetch_flow_collection_end(parser,
+			yaml_FLOW_SEQUENCE_END_TOKEN)
+	}
+
+	// Is it the flow mapping end indicator?
+	if parser.buffer[parser.buffer_pos] == '}' {
+		return yaml_parser_fetch_flow_collection_end(parser,
+			yaml_FLOW_MAPPING_END_TOKEN)
+	}
+
+	// Is it the flow entry indicator?
+	if parser.buffer[parser.buffer_pos] == ',' {
+		return yaml_parser_fetch_flow_entry(parser)
+	}
+
+	// Is it the block entry indicator?
+	if parser.buffer[parser.buffer_pos] == '-' && is_blankz(parser.buffer, parser.buffer_pos+1) {
+		return yaml_parser_fetch_block_entry(parser)
+	}
+
+	// Is it the key indicator?
+	if parser.buffer[parser.buffer_pos] == '?' && (parser.flow_level > 0 || is_blankz(parser.buffer, parser.buffer_pos+1)) {
+		return yaml_parser_fetch_key(parser)
+	}
+
+	// Is it the value indicator?
+	if parser.buffer[parser.buffer_pos] == ':' && (parser.flow_level > 0 || is_blankz(parser.buffer, parser.buffer_pos+1)) {
+		return yaml_parser_fetch_value(parser)
+	}
+
+	// Is it an alias?
+	if parser.buffer[parser.buffer_pos] == '*' {
+		return yaml_parser_fetch_anchor(parser, yaml_ALIAS_TOKEN)
+	}
+
+	// Is it an anchor?
+	if parser.buffer[parser.buffer_pos] == '&' {
+		return yaml_parser_fetch_anchor(parser, yaml_ANCHOR_TOKEN)
+	}
+
+	// Is it a tag?
+	if parser.buffer[parser.buffer_pos] == '!' {
+		return yaml_parser_fetch_tag(parser)
+	}
+
+	// Is it a literal scalar?
+	if parser.buffer[parser.buffer_pos] == '|' && parser.flow_level == 0 {
+		return yaml_parser_fetch_block_scalar(parser, true)
+	}
+
+	// Is it a folded scalar?
+	if parser.buffer[parser.buffer_pos] == '>' && parser.flow_level == 0 {
+		return yaml_parser_fetch_block_scalar(parser, false)
+	}
+
+	// Is it a single-quoted scalar?
+	if parser.buffer[parser.buffer_pos] == '\'' {
+		return yaml_parser_fetch_flow_scalar(parser, true)
+	}
+
+	// Is it a double-quoted scalar?
+	if parser.buffer[parser.buffer_pos] == '"' {
+		return yaml_parser_fetch_flow_scalar(parser, false)
+	}
+
+	// Is it a plain scalar?
+	//
+	// A plain scalar may start with any non-blank characters except
+	//
+	//      '-', '?', ':', ',', '[', ']', '{', '}',
+	//      '#', '&', '*', '!', '|', '>', '\'', '\"',
+	//      '%', '@', '`'.
+	//
+	// In the block context (and, for the '-' indicator, in the flow context
+	// too), it may also start with the characters
+	//
+	//      '-', '?', ':'
+	//
+	// if it is followed by a non-space character.
+	//
+	// The last rule is more restrictive than the specification requires.
+	// [Go] TODO Make this logic more reasonable.
+	//switch parser.buffer[parser.buffer_pos] {
+	//case '-', '?', ':', ',', '?', '-', ',', ':', ']', '[', '}', '{', '&', '#', '!', '*', '>', '|', '"', '\'', '@', '%', '-', '`':
+	//}
+	if !(is_blankz(parser.buffer, parser.buffer_pos) || parser.buffer[parser.buffer_pos] == '-' ||
+		parser.buffer[parser.buffer_pos] == '?' || parser.buffer[parser.buffer_pos] == ':' ||
+		parser.buffer[parser.buffer_pos] == ',' || parser.buffer[parser.buffer_pos] == '[' ||
+		parser.buffer[parser.buffer_pos] == ']' || parser.buffer[parser.buffer_pos] == '{' ||
+		parser.buffer[parser.buffer_pos] == '}' || parser.buffer[parser.buffer_pos] == '#' ||
+		parser.buffer[parser.buffer_pos] == '&' || parser.buffer[parser.buffer_pos] == '*' ||
+		parser.buffer[parser.buffer_pos] == '!' || parser.buffer[parser.buffer_pos] == '|' ||
+		parser.buffer[parser.buffer_pos] == '>' || parser.buffer[parser.buffer_pos] == '\'' ||
+		parser.buffer[parser.buffer_pos] == '"' || parser.buffer[parser.buffer_pos] == '%' ||
+		parser.buffer[parser.buffer_pos] == '@' || parser.buffer[parser.buffer_pos] == '`') ||
+		(parser.buffer[parser.buffer_pos] == '-' && !is_blank(parser.buffer, parser.buffer_pos+1)) ||
+		(parser.flow_level == 0 &&
+			(parser.buffer[parser.buffer_pos] == '?' || parser.buffer[parser.buffer_pos] == ':') &&
+			!is_blankz(parser.buffer, parser.buffer_pos+1)) {
+		return yaml_parser_fetch_plain_scalar(parser)
+	}
+
+	// If we don't determine the token type so far, it is an error.
+	return yaml_parser_set_scanner_error(parser,
+		"while scanning for the next token", parser.mark,
+		"found character that cannot start any token")
+}
+
+func yaml_simple_key_is_valid(parser *yaml_parser_t, simple_key *yaml_simple_key_t) (valid, ok bool) {
+	if !simple_key.possible {
+		return false, true
+	}
+
+	// The 1.2 specification says:
+	//
+	//     "If the ? indicator is omitted, parsing needs to see past the
+	//     implicit key to recognize it as such. To limit the amount of
+	//     lookahead required, the “:” indicator must appear at most 1024
+	//     Unicode characters beyond the start of the key. In addition, the key
+	//     is restricted to a single line."
+	//
+	if simple_key.mark.line < parser.mark.line || simple_key.mark.index+1024 < parser.mark.index {
+		// Check if the potential simple key to be removed is required.
+		if simple_key.required {
+			return false, yaml_parser_set_scanner_error(parser,
+				"while scanning a simple key", simple_key.mark,
+				"could not find expected ':'")
+		}
+		simple_key.possible = false
+		return false, true
+	}
+	return true, true
+}
+
+// Check if a simple key may start at the current position and add it if
+// needed.
+func yaml_parser_save_simple_key(parser *yaml_parser_t) bool {
+	// A simple key is required at the current position if the scanner is in
+	// the block context and the current column coincides with the indentation
+	// level.
+
+	required := parser.flow_level == 0 && parser.indent == parser.mark.column
+
+	//
+	// If the current position may start a simple key, save it.
+	//
+	if parser.simple_key_allowed {
+		simple_key := yaml_simple_key_t{
+			possible:     true,
+			required:     required,
+			token_number: parser.tokens_parsed + (len(parser.tokens) - parser.tokens_head),
+			mark:         parser.mark,
+		}
+
+		if !yaml_parser_remove_simple_key(parser) {
+			return false
+		}
+		parser.simple_keys[len(parser.simple_keys)-1] = simple_key
+		parser.simple_keys_by_tok[simple_key.token_number] = len(parser.simple_keys) - 1
+	}
+	return true
+}
+
+// Remove a potential simple key at the current flow level.
+func yaml_parser_remove_simple_key(parser *yaml_parser_t) bool {
+	i := len(parser.simple_keys) - 1
+	if parser.simple_keys[i].possible {
+		// If the key is required, it is an error.
+		if parser.simple_keys[i].required {
+			return yaml_parser_set_scanner_error(parser,
+				"while scanning a simple key", parser.simple_keys[i].mark,
+				"could not find expected ':'")
+		}
+		// Remove the key from the stack.
+		parser.simple_keys[i].possible = false
+		delete(parser.simple_keys_by_tok, parser.simple_keys[i].token_number)
+	}
+	return true
+}
+
+// max_flow_level limits the flow_level
+const max_flow_level = 10000
+
+// Increase the flow level and resize the simple key list if needed.
+func yaml_parser_increase_flow_level(parser *yaml_parser_t) bool {
+	// Reset the simple key on the next level.
+	parser.simple_keys = append(parser.simple_keys, yaml_simple_key_t{
+		possible:     false,
+		required:     false,
+		token_number: parser.tokens_parsed + (len(parser.tokens) - parser.tokens_head),
+		mark:         parser.mark,
+	})
+
+	// Increase the flow level.
+	parser.flow_level++
+	if parser.flow_level > max_flow_level {
+		return yaml_parser_set_scanner_error(parser,
+			"while increasing flow level", parser.simple_keys[len(parser.simple_keys)-1].mark,
+			fmt.Sprintf("exceeded max depth of %d", max_flow_level))
+	}
+	return true
+}
+
+// Decrease the flow level.
+func yaml_parser_decrease_flow_level(parser *yaml_parser_t) bool {
+	if parser.flow_level > 0 {
+		parser.flow_level--
+		last := len(parser.simple_keys) - 1
+		delete(parser.simple_keys_by_tok, parser.simple_keys[last].token_number)
+		parser.simple_keys = parser.simple_keys[:last]
+	}
+	return true
+}
+
+// max_indents limits the indents stack size
+const max_indents = 10000
+
+// Push the current indentation level to the stack and set the new level
+// the current column is greater than the indentation level.  In this case,
+// append or insert the specified token into the token queue.
+func yaml_parser_roll_indent(parser *yaml_parser_t, column, number int, typ yaml_token_type_t, mark yaml_mark_t) bool {
+	// In the flow context, do nothing.
+	if parser.flow_level > 0 {
+		return true
+	}
+
+	if parser.indent < column {
+		// Push the current indentation level to the stack and set the new
+		// indentation level.
+		parser.indents = append(parser.indents, parser.indent)
+		parser.indent = column
+		if len(parser.indents) > max_indents {
+			return yaml_parser_set_scanner_error(parser,
+				"while increasing indent level", parser.simple_keys[len(parser.simple_keys)-1].mark,
+				fmt.Sprintf("exceeded max depth of %d", max_indents))
+		}
+
+		// Create a token and insert it into the queue.
+		token := yaml_token_t{
+			typ:        typ,
+			start_mark: mark,
+			end_mark:   mark,
+		}
+		if number > -1 {
+			number -= parser.tokens_parsed
+		}
+		yaml_insert_token(parser, number, &token)
+	}
+	return true
+}
+
+// Pop indentation levels from the indents stack until the current level
+// becomes less or equal to the column.  For each indentation level, append
+// the BLOCK-END token.
+func yaml_parser_unroll_indent(parser *yaml_parser_t, column int, scan_mark yaml_mark_t) bool {
+	// In the flow context, do nothing.
+	if parser.flow_level > 0 {
+		return true
+	}
+
+	block_mark := scan_mark
+	block_mark.index--
+
+	// Loop through the indentation levels in the stack.
+	for parser.indent > column {
+
+		// [Go] Reposition the end token before potential following
+		//      foot comments of parent blocks. For that, search
+		//      backwards for recent comments that were at the same
+		//      indent as the block that is ending now.
+		stop_index := block_mark.index
+		for i := len(parser.comments) - 1; i >= 0; i-- {
+			comment := &parser.comments[i]
+
+			if comment.end_mark.index < stop_index {
+				// Don't go back beyond the start of the comment/whitespace scan, unless column < 0.
+				// If requested indent column is < 0, then the document is over and everything else
+				// is a foot anyway.
+				break
+			}
+			if comment.start_mark.column == parser.indent+1 {
+				// This is a good match. But maybe there's a former comment
+				// at that same indent level, so keep searching.
+				block_mark = comment.start_mark
+			}
+
+			// While the end of the former comment matches with
+			// the start of the following one, we know there's
+			// nothing in between and scanning is still safe.
+			stop_index = comment.scan_mark.index
+		}
+
+		// Create a token and append it to the queue.
+		token := yaml_token_t{
+			typ:        yaml_BLOCK_END_TOKEN,
+			start_mark: block_mark,
+			end_mark:   block_mark,
+		}
+		yaml_insert_token(parser, -1, &token)
+
+		// Pop the indentation level.
+		parser.indent = parser.indents[len(parser.indents)-1]
+		parser.indents = parser.indents[:len(parser.indents)-1]
+	}
+	return true
+}
+
+// Initialize the scanner and produce the STREAM-START token.
+func yaml_parser_fetch_stream_start(parser *yaml_parser_t) bool {
+
+	// Set the initial indentation.
+	parser.indent = -1
+
+	// Initialize the simple key stack.
+	parser.simple_keys = append(parser.simple_keys, yaml_simple_key_t{})
+
+	parser.simple_keys_by_tok = make(map[int]int)
+
+	// A simple key is allowed at the beginning of the stream.
+	parser.simple_key_allowed = true
+
+	// We have started.
+	parser.stream_start_produced = true
+
+	// Create the STREAM-START token and append it to the queue.
+	token := yaml_token_t{
+		typ:        yaml_STREAM_START_TOKEN,
+		start_mark: parser.mark,
+		end_mark:   parser.mark,
+		encoding:   parser.encoding,
+	}
+	yaml_insert_token(parser, -1, &token)
+	return true
+}
+
+// Produce the STREAM-END token and shut down the scanner.
+func yaml_parser_fetch_stream_end(parser *yaml_parser_t) bool {
+
+	// Force new line.
+	if parser.mark.column != 0 {
+		parser.mark.column = 0
+		parser.mark.line++
+	}
+
+	// Reset the indentation level.
+	if !yaml_parser_unroll_indent(parser, -1, parser.mark) {
+		return false
+	}
+
+	// Reset simple keys.
+	if !yaml_parser_remove_simple_key(parser) {
+		return false
+	}
+
+	parser.simple_key_allowed = false
+
+	// Create the STREAM-END token and append it to the queue.
+	token := yaml_token_t{
+		typ:        yaml_STREAM_END_TOKEN,
+		start_mark: parser.mark,
+		end_mark:   parser.mark,
+	}
+	yaml_insert_token(parser, -1, &token)
+	return true
+}
+
+// Produce a VERSION-DIRECTIVE or TAG-DIRECTIVE token.
+func yaml_parser_fetch_directive(parser *yaml_parser_t) bool {
+	// Reset the indentation level.
+	if !yaml_parser_unroll_indent(parser, -1, parser.mark) {
+		return false
+	}
+
+	// Reset simple keys.
+	if !yaml_parser_remove_simple_key(parser) {
+		return false
+	}
+
+	parser.simple_key_allowed = false
+
+	// Create the YAML-DIRECTIVE or TAG-DIRECTIVE token.
+	token := yaml_token_t{}
+	if !yaml_parser_scan_directive(parser, &token) {
+		return false
+	}
+	// Append the token to the queue.
+	yaml_insert_token(parser, -1, &token)
+	return true
+}
+
+// Produce the DOCUMENT-START or DOCUMENT-END token.
+func yaml_parser_fetch_document_indicator(parser *yaml_parser_t, typ yaml_token_type_t) bool {
+	// Reset the indentation level.
+	if !yaml_parser_unroll_indent(parser, -1, parser.mark) {
+		return false
+	}
+
+	// Reset simple keys.
+	if !yaml_parser_remove_simple_key(parser) {
+		return false
+	}
+
+	parser.simple_key_allowed = false
+
+	// Consume the token.
+	start_mark := parser.mark
+
+	skip(parser)
+	skip(parser)
+	skip(parser)
+
+	end_mark := parser.mark
+
+	// Create the DOCUMENT-START or DOCUMENT-END token.
+	token := yaml_token_t{
+		typ:        typ,
+		start_mark: start_mark,
+		end_mark:   end_mark,
+	}
+	// Append the token to the queue.
+	yaml_insert_token(parser, -1, &token)
+	return true
+}
+
+// Produce the FLOW-SEQUENCE-START or FLOW-MAPPING-START token.
+func yaml_parser_fetch_flow_collection_start(parser *yaml_parser_t, typ yaml_token_type_t) bool {
+
+	// The indicators '[' and '{' may start a simple key.
+	if !yaml_parser_save_simple_key(parser) {
+		return false
+	}
+
+	// Increase the flow level.
+	if !yaml_parser_increase_flow_level(parser) {
+		return false
+	}
+
+	// A simple key may follow the indicators '[' and '{'.
+	parser.simple_key_allowed = true
+
+	// Consume the token.
+	start_mark := parser.mark
+	skip(parser)
+	end_mark := parser.mark
+
+	// Create the FLOW-SEQUENCE-START of FLOW-MAPPING-START token.
+	token := yaml_token_t{
+		typ:        typ,
+		start_mark: start_mark,
+		end_mark:   end_mark,
+	}
+	// Append the token to the queue.
+	yaml_insert_token(parser, -1, &token)
+	return true
+}
+
+// Produce the FLOW-SEQUENCE-END or FLOW-MAPPING-END token.
+func yaml_parser_fetch_flow_collection_end(parser *yaml_parser_t, typ yaml_token_type_t) bool {
+	// Reset any potential simple key on the current flow level.
+	if !yaml_parser_remove_simple_key(parser) {
+		return false
+	}
+
+	// Decrease the flow level.
+	if !yaml_parser_decrease_flow_level(parser) {
+		return false
+	}
+
+	// No simple keys after the indicators ']' and '}'.
+	parser.simple_key_allowed = false
+
+	// Consume the token.
+
+	start_mark := parser.mark
+	skip(parser)
+	end_mark := parser.mark
+
+	// Create the FLOW-SEQUENCE-END of FLOW-MAPPING-END token.
+	token := yaml_token_t{
+		typ:        typ,
+		start_mark: start_mark,
+		end_mark:   end_mark,
+	}
+	// Append the token to the queue.
+	yaml_insert_token(parser, -1, &token)
+	return true
+}
+
+// Produce the FLOW-ENTRY token.
+func yaml_parser_fetch_flow_entry(parser *yaml_parser_t) bool {
+	// Reset any potential simple keys on the current flow level.
+	if !yaml_parser_remove_simple_key(parser) {
+		return false
+	}
+
+	// Simple keys are allowed after ','.
+	parser.simple_key_allowed = true
+
+	// Consume the token.
+	start_mark := parser.mark
+	skip(parser)
+	end_mark := parser.mark
+
+	// Create the FLOW-ENTRY token and append it to the queue.
+	token := yaml_token_t{
+		typ:        yaml_FLOW_ENTRY_TOKEN,
+		start_mark: start_mark,
+		end_mark:   end_mark,
+	}
+	yaml_insert_token(parser, -1, &token)
+	return true
+}
+
+// Produce the BLOCK-ENTRY token.
+func yaml_parser_fetch_block_entry(parser *yaml_parser_t) bool {
+	// Check if the scanner is in the block context.
+	if parser.flow_level == 0 {
+		// Check if we are allowed to start a new entry.
+		if !parser.simple_key_allowed {
+			return yaml_parser_set_scanner_error(parser, "", parser.mark,
+				"block sequence entries are not allowed in this context")
+		}
+		// Add the BLOCK-SEQUENCE-START token if needed.
+		if !yaml_parser_roll_indent(parser, parser.mark.column, -1, yaml_BLOCK_SEQUENCE_START_TOKEN, parser.mark) {
+			return false
+		}
+	} else {
+		// It is an error for the '-' indicator to occur in the flow context,
+		// but we let the Parser detect and report about it because the Parser
+		// is able to point to the context.
+	}
+
+	// Reset any potential simple keys on the current flow level.
+	if !yaml_parser_remove_simple_key(parser) {
+		return false
+	}
+
+	// Simple keys are allowed after '-'.
+	parser.simple_key_allowed = true
+
+	// Consume the token.
+	start_mark := parser.mark
+	skip(parser)
+	end_mark := parser.mark
+
+	// Create the BLOCK-ENTRY token and append it to the queue.
+	token := yaml_token_t{
+		typ:        yaml_BLOCK_ENTRY_TOKEN,
+		start_mark: start_mark,
+		end_mark:   end_mark,
+	}
+	yaml_insert_token(parser, -1, &token)
+	return true
+}
+
+// Produce the KEY token.
+func yaml_parser_fetch_key(parser *yaml_parser_t) bool {
+
+	// In the block context, additional checks are required.
+	if parser.flow_level == 0 {
+		// Check if we are allowed to start a new key (not nessesary simple).
+		if !parser.simple_key_allowed {
+			return yaml_parser_set_scanner_error(parser, "", parser.mark,
+				"mapping keys are not allowed in this context")
+		}
+		// Add the BLOCK-MAPPING-START token if needed.
+		if !yaml_parser_roll_indent(parser, parser.mark.column, -1, yaml_BLOCK_MAPPING_START_TOKEN, parser.mark) {
+			return false
+		}
+	}
+
+	// Reset any potential simple keys on the current flow level.
+	if !yaml_parser_remove_simple_key(parser) {
+		return false
+	}
+
+	// Simple keys are allowed after '?' in the block context.
+	parser.simple_key_allowed = parser.flow_level == 0
+
+	// Consume the token.
+	start_mark := parser.mark
+	skip(parser)
+	end_mark := parser.mark
+
+	// Create the KEY token and append it to the queue.
+	token := yaml_token_t{
+		typ:        yaml_KEY_TOKEN,
+		start_mark: start_mark,
+		end_mark:   end_mark,
+	}
+	yaml_insert_token(parser, -1, &token)
+	return true
+}
+
+// Produce the VALUE token.
+func yaml_parser_fetch_value(parser *yaml_parser_t) bool {
+
+	simple_key := &parser.simple_keys[len(parser.simple_keys)-1]
+
+	// Have we found a simple key?
+	if valid, ok := yaml_simple_key_is_valid(parser, simple_key); !ok {
+		return false
+
+	} else if valid {
+
+		// Create the KEY token and insert it into the queue.
+		token := yaml_token_t{
+			typ:        yaml_KEY_TOKEN,
+			start_mark: simple_key.mark,
+			end_mark:   simple_key.mark,
+		}
+		yaml_insert_token(parser, simple_key.token_number-parser.tokens_parsed, &token)
+
+		// In the block context, we may need to add the BLOCK-MAPPING-START token.
+		if !yaml_parser_roll_indent(parser, simple_key.mark.column,
+			simple_key.token_number,
+			yaml_BLOCK_MAPPING_START_TOKEN, simple_key.mark) {
+			return false
+		}
+
+		// Remove the simple key.
+		simple_key.possible = false
+		delete(parser.simple_keys_by_tok, simple_key.token_number)
+
+		// A simple key cannot follow another simple key.
+		parser.simple_key_allowed = false
+
+	} else {
+		// The ':' indicator follows a complex key.
+
+		// In the block context, extra checks are required.
+		if parser.flow_level == 0 {
+
+			// Check if we are allowed to start a complex value.
+			if !parser.simple_key_allowed {
+				return yaml_parser_set_scanner_error(parser, "", parser.mark,
+					"mapping values are not allowed in this context")
+			}
+
+			// Add the BLOCK-MAPPING-START token if needed.
+			if !yaml_parser_roll_indent(parser, parser.mark.column, -1, yaml_BLOCK_MAPPING_START_TOKEN, parser.mark) {
+				return false
+			}
+		}
+
+		// Simple keys after ':' are allowed in the block context.
+		parser.simple_key_allowed = parser.flow_level == 0
+	}
+
+	// Consume the token.
+	start_mark := parser.mark
+	skip(parser)
+	end_mark := parser.mark
+
+	// Create the VALUE token and append it to the queue.
+	token := yaml_token_t{
+		typ:        yaml_VALUE_TOKEN,
+		start_mark: start_mark,
+		end_mark:   end_mark,
+	}
+	yaml_insert_token(parser, -1, &token)
+	return true
+}
+
+// Produce the ALIAS or ANCHOR token.
+func yaml_parser_fetch_anchor(parser *yaml_parser_t, typ yaml_token_type_t) bool {
+	// An anchor or an alias could be a simple key.
+	if !yaml_parser_save_simple_key(parser) {
+		return false
+	}
+
+	// A simple key cannot follow an anchor or an alias.
+	parser.simple_key_allowed = false
+
+	// Create the ALIAS or ANCHOR token and append it to the queue.
+	var token yaml_token_t
+	if !yaml_parser_scan_anchor(parser, &token, typ) {
+		return false
+	}
+	yaml_insert_token(parser, -1, &token)
+	return true
+}
+
+// Produce the TAG token.
+func yaml_parser_fetch_tag(parser *yaml_parser_t) bool {
+	// A tag could be a simple key.
+	if !yaml_parser_save_simple_key(parser) {
+		return false
+	}
+
+	// A simple key cannot follow a tag.
+	parser.simple_key_allowed = false
+
+	// Create the TAG token and append it to the queue.
+	var token yaml_token_t
+	if !yaml_parser_scan_tag(parser, &token) {
+		return false
+	}
+	yaml_insert_token(parser, -1, &token)
+	return true
+}
+
+// Produce the SCALAR(...,literal) or SCALAR(...,folded) tokens.
+func yaml_parser_fetch_block_scalar(parser *yaml_parser_t, literal bool) bool {
+	// Remove any potential simple keys.
+	if !yaml_parser_remove_simple_key(parser) {
+		return false
+	}
+
+	// A simple key may follow a block scalar.
+	parser.simple_key_allowed = true
+
+	// Create the SCALAR token and append it to the queue.
+	var token yaml_token_t
+	if !yaml_parser_scan_block_scalar(parser, &token, literal) {
+		return false
+	}
+	yaml_insert_token(parser, -1, &token)
+	return true
+}
+
+// Produce the SCALAR(...,single-quoted) or SCALAR(...,double-quoted) tokens.
+func yaml_parser_fetch_flow_scalar(parser *yaml_parser_t, single bool) bool {
+	// A plain scalar could be a simple key.
+	if !yaml_parser_save_simple_key(parser) {
+		return false
+	}
+
+	// A simple key cannot follow a flow scalar.
+	parser.simple_key_allowed = false
+
+	// Create the SCALAR token and append it to the queue.
+	var token yaml_token_t
+	if !yaml_parser_scan_flow_scalar(parser, &token, single) {
+		return false
+	}
+	yaml_insert_token(parser, -1, &token)
+	return true
+}
+
+// Produce the SCALAR(...,plain) token.
+func yaml_parser_fetch_plain_scalar(parser *yaml_parser_t) bool {
+	// A plain scalar could be a simple key.
+	if !yaml_parser_save_simple_key(parser) {
+		return false
+	}
+
+	// A simple key cannot follow a flow scalar.
+	parser.simple_key_allowed = false
+
+	// Create the SCALAR token and append it to the queue.
+	var token yaml_token_t
+	if !yaml_parser_scan_plain_scalar(parser, &token) {
+		return false
+	}
+	yaml_insert_token(parser, -1, &token)
+	return true
+}
+
+// Eat whitespaces and comments until the next token is found.
+func yaml_parser_scan_to_next_token(parser *yaml_parser_t) bool {
+
+	scan_mark := parser.mark
+
+	// Until the next token is not found.
+	for {
+		// Allow the BOM mark to start a line.
+		if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+			return false
+		}
+		if parser.mark.column == 0 && is_bom(parser.buffer, parser.buffer_pos) {
+			skip(parser)
+		}
+
+		// Eat whitespaces.
+		// Tabs are allowed:
+		//  - in the flow context
+		//  - in the block context, but not at the beginning of the line or
+		//  after '-', '?', or ':' (complex value).
+		if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+			return false
+		}
+
+		for parser.buffer[parser.buffer_pos] == ' ' || ((parser.flow_level > 0 || !parser.simple_key_allowed) && parser.buffer[parser.buffer_pos] == '\t') {
+			skip(parser)
+			if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+				return false
+			}
+		}
+
+		// Check if we just had a line comment under a sequence entry that
+		// looks more like a header to the following content. Similar to this:
+		//
+		// - # The comment
+		//   - Some data
+		//
+		// If so, transform the line comment to a head comment and reposition.
+		if len(parser.comments) > 0 && len(parser.tokens) > 1 {
+			tokenA := parser.tokens[len(parser.tokens)-2]
+			tokenB := parser.tokens[len(parser.tokens)-1]
+			comment := &parser.comments[len(parser.comments)-1]
+			if tokenA.typ == yaml_BLOCK_SEQUENCE_START_TOKEN && tokenB.typ == yaml_BLOCK_ENTRY_TOKEN && len(comment.line) > 0 && !is_break(parser.buffer, parser.buffer_pos) {
+				// If it was in the prior line, reposition so it becomes a
+				// header of the follow up token. Otherwise, keep it in place
+				// so it becomes a header of the former.
+				comment.head = comment.line
+				comment.line = nil
+				if comment.start_mark.line == parser.mark.line-1 {
+					comment.token_mark = parser.mark
+				}
+			}
+		}
+
+		// Eat a comment until a line break.
+		if parser.buffer[parser.buffer_pos] == '#' {
+			if !yaml_parser_scan_comments(parser, scan_mark) {
+				return false
+			}
+		}
+
+		// If it is a line break, eat it.
+		if is_break(parser.buffer, parser.buffer_pos) {
+			if parser.unread < 2 && !yaml_parser_update_buffer(parser, 2) {
+				return false
+			}
+			skip_line(parser)
+
+			// In the block context, a new line may start a simple key.
+			if parser.flow_level == 0 {
+				parser.simple_key_allowed = true
+			}
+		} else {
+			break // We have found a token.
+		}
+	}
+
+	return true
+}
+
+// Scan a YAML-DIRECTIVE or TAG-DIRECTIVE token.
+//
+// Scope:
+//      %YAML    1.1    # a comment \n
+//      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+//      %TAG    !yaml!  tag:yaml.org,2002:  \n
+//      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+//
+func yaml_parser_scan_directive(parser *yaml_parser_t, token *yaml_token_t) bool {
+	// Eat '%'.
+	start_mark := parser.mark
+	skip(parser)
+
+	// Scan the directive name.
+	var name []byte
+	if !yaml_parser_scan_directive_name(parser, start_mark, &name) {
+		return false
+	}
+
+	// Is it a YAML directive?
+	if bytes.Equal(name, []byte("YAML")) {
+		// Scan the VERSION directive value.
+		var major, minor int8
+		if !yaml_parser_scan_version_directive_value(parser, start_mark, &major, &minor) {
+			return false
+		}
+		end_mark := parser.mark
+
+		// Create a VERSION-DIRECTIVE token.
+		*token = yaml_token_t{
+			typ:        yaml_VERSION_DIRECTIVE_TOKEN,
+			start_mark: start_mark,
+			end_mark:   end_mark,
+			major:      major,
+			minor:      minor,
+		}
+
+		// Is it a TAG directive?
+	} else if bytes.Equal(name, []byte("TAG")) {
+		// Scan the TAG directive value.
+		var handle, prefix []byte
+		if !yaml_parser_scan_tag_directive_value(parser, start_mark, &handle, &prefix) {
+			return false
+		}
+		end_mark := parser.mark
+
+		// Create a TAG-DIRECTIVE token.
+		*token = yaml_token_t{
+			typ:        yaml_TAG_DIRECTIVE_TOKEN,
+			start_mark: start_mark,
+			end_mark:   end_mark,
+			value:      handle,
+			prefix:     prefix,
+		}
+
+		// Unknown directive.
+	} else {
+		yaml_parser_set_scanner_error(parser, "while scanning a directive",
+			start_mark, "found unknown directive name")
+		return false
+	}
+
+	// Eat the rest of the line including any comments.
+	if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+		return false
+	}
+
+	for is_blank(parser.buffer, parser.buffer_pos) {
+		skip(parser)
+		if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+			return false
+		}
+	}
+
+	if parser.buffer[parser.buffer_pos] == '#' {
+		// [Go] Discard this inline comment for the time being.
+		//if !yaml_parser_scan_line_comment(parser, start_mark) {
+		//	return false
+		//}
+		for !is_breakz(parser.buffer, parser.buffer_pos) {
+			skip(parser)
+			if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+				return false
+			}
+		}
+	}
+
+	// Check if we are at the end of the line.
+	if !is_breakz(parser.buffer, parser.buffer_pos) {
+		yaml_parser_set_scanner_error(parser, "while scanning a directive",
+			start_mark, "did not find expected comment or line break")
+		return false
+	}
+
+	// Eat a line break.
+	if is_break(parser.buffer, parser.buffer_pos) {
+		if parser.unread < 2 && !yaml_parser_update_buffer(parser, 2) {
+			return false
+		}
+		skip_line(parser)
+	}
+
+	return true
+}
+
+// Scan the directive name.
+//
+// Scope:
+//      %YAML   1.1     # a comment \n
+//       ^^^^
+//      %TAG    !yaml!  tag:yaml.org,2002:  \n
+//       ^^^
+//
+func yaml_parser_scan_directive_name(parser *yaml_parser_t, start_mark yaml_mark_t, name *[]byte) bool {
+	// Consume the directive name.
+	if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+		return false
+	}
+
+	var s []byte
+	for is_alpha(parser.buffer, parser.buffer_pos) {
+		s = read(parser, s)
+		if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+			return false
+		}
+	}
+
+	// Check if the name is empty.
+	if len(s) == 0 {
+		yaml_parser_set_scanner_error(parser, "while scanning a directive",
+			start_mark, "could not find expected directive name")
+		return false
+	}
+
+	// Check for an blank character after the name.
+	if !is_blankz(parser.buffer, parser.buffer_pos) {
+		yaml_parser_set_scanner_error(parser, "while scanning a directive",
+			start_mark, "found unexpected non-alphabetical character")
+		return false
+	}
+	*name = s
+	return true
+}
+
+// Scan the value of VERSION-DIRECTIVE.
+//
+// Scope:
+//      %YAML   1.1     # a comment \n
+//           ^^^^^^
+func yaml_parser_scan_version_directive_value(parser *yaml_parser_t, start_mark yaml_mark_t, major, minor *int8) bool {
+	// Eat whitespaces.
+	if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+		return false
+	}
+	for is_blank(parser.buffer, parser.buffer_pos) {
+		skip(parser)
+		if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+			return false
+		}
+	}
+
+	// Consume the major version number.
+	if !yaml_parser_scan_version_directive_number(parser, start_mark, major) {
+		return false
+	}
+
+	// Eat '.'.
+	if parser.buffer[parser.buffer_pos] != '.' {
+		return yaml_parser_set_scanner_error(parser, "while scanning a %YAML directive",
+			start_mark, "did not find expected digit or '.' character")
+	}
+
+	skip(parser)
+
+	// Consume the minor version number.
+	if !yaml_parser_scan_version_directive_number(parser, start_mark, minor) {
+		return false
+	}
+	return true
+}
+
+const max_number_length = 2
+
+// Scan the version number of VERSION-DIRECTIVE.
+//
+// Scope:
+//      %YAML   1.1     # a comment \n
+//              ^
+//      %YAML   1.1     # a comment \n
+//                ^
+func yaml_parser_scan_version_directive_number(parser *yaml_parser_t, start_mark yaml_mark_t, number *int8) bool {
+
+	// Repeat while the next character is digit.
+	if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+		return false
+	}
+	var value, length int8
+	for is_digit(parser.buffer, parser.buffer_pos) {
+		// Check if the number is too long.
+		length++
+		if length > max_number_length {
+			return yaml_parser_set_scanner_error(parser, "while scanning a %YAML directive",
+				start_mark, "found extremely long version number")
+		}
+		value = value*10 + int8(as_digit(parser.buffer, parser.buffer_pos))
+		skip(parser)
+		if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+			return false
+		}
+	}
+
+	// Check if the number was present.
+	if length == 0 {
+		return yaml_parser_set_scanner_error(parser, "while scanning a %YAML directive",
+			start_mark, "did not find expected version number")
+	}
+	*number = value
+	return true
+}
+
+// Scan the value of a TAG-DIRECTIVE token.
+//
+// Scope:
+//      %TAG    !yaml!  tag:yaml.org,2002:  \n
+//          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+//
+func yaml_parser_scan_tag_directive_value(parser *yaml_parser_t, start_mark yaml_mark_t, handle, prefix *[]byte) bool {
+	var handle_value, prefix_value []byte
+
+	// Eat whitespaces.
+	if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+		return false
+	}
+
+	for is_blank(parser.buffer, parser.buffer_pos) {
+		skip(parser)
+		if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+			return false
+		}
+	}
+
+	// Scan a handle.
+	if !yaml_parser_scan_tag_handle(parser, true, start_mark, &handle_value) {
+		return false
+	}
+
+	// Expect a whitespace.
+	if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+		return false
+	}
+	if !is_blank(parser.buffer, parser.buffer_pos) {
+		yaml_parser_set_scanner_error(parser, "while scanning a %TAG directive",
+			start_mark, "did not find expected whitespace")
+		return false
+	}
+
+	// Eat whitespaces.
+	for is_blank(parser.buffer, parser.buffer_pos) {
+		skip(parser)
+		if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+			return false
+		}
+	}
+
+	// Scan a prefix.
+	if !yaml_parser_scan_tag_uri(parser, true, nil, start_mark, &prefix_value) {
+		return false
+	}
+
+	// Expect a whitespace or line break.
+	if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+		return false
+	}
+	if !is_blankz(parser.buffer, parser.buffer_pos) {
+		yaml_parser_set_scanner_error(parser, "while scanning a %TAG directive",
+			start_mark, "did not find expected whitespace or line break")
+		return false
+	}
+
+	*handle = handle_value
+	*prefix = prefix_value
+	return true
+}
+
+func yaml_parser_scan_anchor(parser *yaml_parser_t, token *yaml_token_t, typ yaml_token_type_t) bool {
+	var s []byte
+
+	// Eat the indicator character.
+	start_mark := parser.mark
+	skip(parser)
+
+	// Consume the value.
+	if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+		return false
+	}
+
+	for is_alpha(parser.buffer, parser.buffer_pos) {
+		s = read(parser, s)
+		if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+			return false
+		}
+	}
+
+	end_mark := parser.mark
+
+	/*
+	 * Check if length of the anchor is greater than 0 and it is followed by
+	 * a whitespace character or one of the indicators:
+	 *
+	 *      '?', ':', ',', ']', '}', '%', '@', '`'.
+	 */
+
+	if len(s) == 0 ||
+		!(is_blankz(parser.buffer, parser.buffer_pos) || parser.buffer[parser.buffer_pos] == '?' ||
+			parser.buffer[parser.buffer_pos] == ':' || parser.buffer[parser.buffer_pos] == ',' ||
+			parser.buffer[parser.buffer_pos] == ']' || parser.buffer[parser.buffer_pos] == '}' ||
+			parser.buffer[parser.buffer_pos] == '%' || parser.buffer[parser.buffer_pos] == '@' ||
+			parser.buffer[parser.buffer_pos] == '`') {
+		context := "while scanning an alias"
+		if typ == yaml_ANCHOR_TOKEN {
+			context = "while scanning an anchor"
+		}
+		yaml_parser_set_scanner_error(parser, context, start_mark,
+			"did not find expected alphabetic or numeric character")
+		return false
+	}
+
+	// Create a token.
+	*token = yaml_token_t{
+		typ:        typ,
+		start_mark: start_mark,
+		end_mark:   end_mark,
+		value:      s,
+	}
+
+	return true
+}
+
+/*
+ * Scan a TAG token.
+ */
+
+func yaml_parser_scan_tag(parser *yaml_parser_t, token *yaml_token_t) bool {
+	var handle, suffix []byte
+
+	start_mark := parser.mark
+
+	// Check if the tag is in the canonical form.
+	if parser.unread < 2 && !yaml_parser_update_buffer(parser, 2) {
+		return false
+	}
+
+	if parser.buffer[parser.buffer_pos+1] == '<' {
+		// Keep the handle as ''
+
+		// Eat '!<'
+		skip(parser)
+		skip(parser)
+
+		// Consume the tag value.
+		if !yaml_parser_scan_tag_uri(parser, false, nil, start_mark, &suffix) {
+			return false
+		}
+
+		// Check for '>' and eat it.
+		if parser.buffer[parser.buffer_pos] != '>' {
+			yaml_parser_set_scanner_error(parser, "while scanning a tag",
+				start_mark, "did not find the expected '>'")
+			return false
+		}
+
+		skip(parser)
+	} else {
+		// The tag has either the '!suffix' or the '!handle!suffix' form.
+
+		// First, try to scan a handle.
+		if !yaml_parser_scan_tag_handle(parser, false, start_mark, &handle) {
+			return false
+		}
+
+		// Check if it is, indeed, handle.
+		if handle[0] == '!' && len(handle) > 1 && handle[len(handle)-1] == '!' {
+			// Scan the suffix now.
+			if !yaml_parser_scan_tag_uri(parser, false, nil, start_mark, &suffix) {
+				return false
+			}
+		} else {
+			// It wasn't a handle after all.  Scan the rest of the tag.
+			if !yaml_parser_scan_tag_uri(parser, false, handle, start_mark, &suffix) {
+				return false
+			}
+
+			// Set the handle to '!'.
+			handle = []byte{'!'}
+
+			// A special case: the '!' tag.  Set the handle to '' and the
+			// suffix to '!'.
+			if len(suffix) == 0 {
+				handle, suffix = suffix, handle
+			}
+		}
+	}
+
+	// Check the character which ends the tag.
+	if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+		return false
+	}
+	if !is_blankz(parser.buffer, parser.buffer_pos) {
+		yaml_parser_set_scanner_error(parser, "while scanning a tag",
+			start_mark, "did not find expected whitespace or line break")
+		return false
+	}
+
+	end_mark := parser.mark
+
+	// Create a token.
+	*token = yaml_token_t{
+		typ:        yaml_TAG_TOKEN,
+		start_mark: start_mark,
+		end_mark:   end_mark,
+		value:      handle,
+		suffix:     suffix,
+	}
+	return true
+}
+
+// Scan a tag handle.
+func yaml_parser_scan_tag_handle(parser *yaml_parser_t, directive bool, start_mark yaml_mark_t, handle *[]byte) bool {
+	// Check the initial '!' character.
+	if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+		return false
+	}
+	if parser.buffer[parser.buffer_pos] != '!' {
+		yaml_parser_set_scanner_tag_error(parser, directive,
+			start_mark, "did not find expected '!'")
+		return false
+	}
+
+	var s []byte
+
+	// Copy the '!' character.
+	s = read(parser, s)
+
+	// Copy all subsequent alphabetical and numerical characters.
+	if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+		return false
+	}
+	for is_alpha(parser.buffer, parser.buffer_pos) {
+		s = read(parser, s)
+		if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+			return false
+		}
+	}
+
+	// Check if the trailing character is '!' and copy it.
+	if parser.buffer[parser.buffer_pos] == '!' {
+		s = read(parser, s)
+	} else {
+		// It's either the '!' tag or not really a tag handle.  If it's a %TAG
+		// directive, it's an error.  If it's a tag token, it must be a part of URI.
+		if directive && string(s) != "!" {
+			yaml_parser_set_scanner_tag_error(parser, directive,
+				start_mark, "did not find expected '!'")
+			return false
+		}
+	}
+
+	*handle = s
+	return true
+}
+
+// Scan a tag.
+func yaml_parser_scan_tag_uri(parser *yaml_parser_t, directive bool, head []byte, start_mark yaml_mark_t, uri *[]byte) bool {
+	//size_t length = head ? strlen((char *)head) : 0
+	var s []byte
+	hasTag := len(head) > 0
+
+	// Copy the head if needed.
+	//
+	// Note that we don't copy the leading '!' character.
+	if len(head) > 1 {
+		s = append(s, head[1:]...)
+	}
+
+	// Scan the tag.
+	if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+		return false
+	}
+
+	// The set of characters that may appear in URI is as follows:
+	//
+	//      '0'-'9', 'A'-'Z', 'a'-'z', '_', '-', ';', '/', '?', ':', '@', '&',
+	//      '=', '+', '$', ',', '.', '!', '~', '*', '\'', '(', ')', '[', ']',
+	//      '%'.
+	// [Go] TODO Convert this into more reasonable logic.
+	for is_alpha(parser.buffer, parser.buffer_pos) || parser.buffer[parser.buffer_pos] == ';' ||
+		parser.buffer[parser.buffer_pos] == '/' || parser.buffer[parser.buffer_pos] == '?' ||
+		parser.buffer[parser.buffer_pos] == ':' || parser.buffer[parser.buffer_pos] == '@' ||
+		parser.buffer[parser.buffer_pos] == '&' || parser.buffer[parser.buffer_pos] == '=' ||
+		parser.buffer[parser.buffer_pos] == '+' || parser.buffer[parser.buffer_pos] == '$' ||
+		parser.buffer[parser.buffer_pos] == ',' || parser.buffer[parser.buffer_pos] == '.' ||
+		parser.buffer[parser.buffer_pos] == '!' || parser.buffer[parser.buffer_pos] == '~' ||
+		parser.buffer[parser.buffer_pos] == '*' || parser.buffer[parser.buffer_pos] == '\'' ||
+		parser.buffer[parser.buffer_pos] == '(' || parser.buffer[parser.buffer_pos] == ')' ||
+		parser.buffer[parser.buffer_pos] == '[' || parser.buffer[parser.buffer_pos] == ']' ||
+		parser.buffer[parser.buffer_pos] == '%' {
+		// Check if it is a URI-escape sequence.
+		if parser.buffer[parser.buffer_pos] == '%' {
+			if !yaml_parser_scan_uri_escapes(parser, directive, start_mark, &s) {
+				return false
+			}
+		} else {
+			s = read(parser, s)
+		}
+		if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+			return false
+		}
+		hasTag = true
+	}
+
+	if !hasTag {
+		yaml_parser_set_scanner_tag_error(parser, directive,
+			start_mark, "did not find expected tag URI")
+		return false
+	}
+	*uri = s
+	return true
+}
+
+// Decode an URI-escape sequence corresponding to a single UTF-8 character.
+func yaml_parser_scan_uri_escapes(parser *yaml_parser_t, directive bool, start_mark yaml_mark_t, s *[]byte) bool {
+
+	// Decode the required number of characters.
+	w := 1024
+	for w > 0 {
+		// Check for a URI-escaped octet.
+		if parser.unread < 3 && !yaml_parser_update_buffer(parser, 3) {
+			return false
+		}
+
+		if !(parser.buffer[parser.buffer_pos] == '%' &&
+			is_hex(parser.buffer, parser.buffer_pos+1) &&
+			is_hex(parser.buffer, parser.buffer_pos+2)) {
+			return yaml_parser_set_scanner_tag_error(parser, directive,
+				start_mark, "did not find URI escaped octet")
+		}
+
+		// Get the octet.
+		octet := byte((as_hex(parser.buffer, parser.buffer_pos+1) << 4) + as_hex(parser.buffer, parser.buffer_pos+2))
+
+		// If it is the leading octet, determine the length of the UTF-8 sequence.
+		if w == 1024 {
+			w = width(octet)
+			if w == 0 {
+				return yaml_parser_set_scanner_tag_error(parser, directive,
+					start_mark, "found an incorrect leading UTF-8 octet")
+			}
+		} else {
+			// Check if the trailing octet is correct.
+			if octet&0xC0 != 0x80 {
+				return yaml_parser_set_scanner_tag_error(parser, directive,
+					start_mark, "found an incorrect trailing UTF-8 octet")
+			}
+		}
+
+		// Copy the octet and move the pointers.
+		*s = append(*s, octet)
+		skip(parser)
+		skip(parser)
+		skip(parser)
+		w--
+	}
+	return true
+}
+
+// Scan a block scalar.
+func yaml_parser_scan_block_scalar(parser *yaml_parser_t, token *yaml_token_t, literal bool) bool {
+	// Eat the indicator '|' or '>'.
+	start_mark := parser.mark
+	skip(parser)
+
+	// Scan the additional block scalar indicators.
+	if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+		return false
+	}
+
+	// Check for a chomping indicator.
+	var chomping, increment int
+	if parser.buffer[parser.buffer_pos] == '+' || parser.buffer[parser.buffer_pos] == '-' {
+		// Set the chomping method and eat the indicator.
+		if parser.buffer[parser.buffer_pos] == '+' {
+			chomping = +1
+		} else {
+			chomping = -1
+		}
+		skip(parser)
+
+		// Check for an indentation indicator.
+		if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+			return false
+		}
+		if is_digit(parser.buffer, parser.buffer_pos) {
+			// Check that the indentation is greater than 0.
+			if parser.buffer[parser.buffer_pos] == '0' {
+				yaml_parser_set_scanner_error(parser, "while scanning a block scalar",
+					start_mark, "found an indentation indicator equal to 0")
+				return false
+			}
+
+			// Get the indentation level and eat the indicator.
+			increment = as_digit(parser.buffer, parser.buffer_pos)
+			skip(parser)
+		}
+
+	} else if is_digit(parser.buffer, parser.buffer_pos) {
+		// Do the same as above, but in the opposite order.
+
+		if parser.buffer[parser.buffer_pos] == '0' {
+			yaml_parser_set_scanner_error(parser, "while scanning a block scalar",
+				start_mark, "found an indentation indicator equal to 0")
+			return false
+		}
+		increment = as_digit(parser.buffer, parser.buffer_pos)
+		skip(parser)
+
+		if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+			return false
+		}
+		if parser.buffer[parser.buffer_pos] == '+' || parser.buffer[parser.buffer_pos] == '-' {
+			if parser.buffer[parser.buffer_pos] == '+' {
+				chomping = +1
+			} else {
+				chomping = -1
+			}
+			skip(parser)
+		}
+	}
+
+	// Eat whitespaces and comments to the end of the line.
+	if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+		return false
+	}
+	for is_blank(parser.buffer, parser.buffer_pos) {
+		skip(parser)
+		if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+			return false
+		}
+	}
+	if parser.buffer[parser.buffer_pos] == '#' {
+		if !yaml_parser_scan_line_comment(parser, start_mark) {
+			return false
+		}
+		for !is_breakz(parser.buffer, parser.buffer_pos) {
+			skip(parser)
+			if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+				return false
+			}
+		}
+	}
+
+	// Check if we are at the end of the line.
+	if !is_breakz(parser.buffer, parser.buffer_pos) {
+		yaml_parser_set_scanner_error(parser, "while scanning a block scalar",
+			start_mark, "did not find expected comment or line break")
+		return false
+	}
+
+	// Eat a line break.
+	if is_break(parser.buffer, parser.buffer_pos) {
+		if parser.unread < 2 && !yaml_parser_update_buffer(parser, 2) {
+			return false
+		}
+		skip_line(parser)
+	}
+
+	end_mark := parser.mark
+
+	// Set the indentation level if it was specified.
+	var indent int
+	if increment > 0 {
+		if parser.indent >= 0 {
+			indent = parser.indent + increment
+		} else {
+			indent = increment
+		}
+	}
+
+	// Scan the leading line breaks and determine the indentation level if needed.
+	var s, leading_break, trailing_breaks []byte
+	if !yaml_parser_scan_block_scalar_breaks(parser, &indent, &trailing_breaks, start_mark, &end_mark) {
+		return false
+	}
+
+	// Scan the block scalar content.
+	if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+		return false
+	}
+	var leading_blank, trailing_blank bool
+	for parser.mark.column == indent && !is_z(parser.buffer, parser.buffer_pos) {
+		// We are at the beginning of a non-empty line.
+
+		// Is it a trailing whitespace?
+		trailing_blank = is_blank(parser.buffer, parser.buffer_pos)
+
+		// Check if we need to fold the leading line break.
+		if !literal && !leading_blank && !trailing_blank && len(leading_break) > 0 && leading_break[0] == '\n' {
+			// Do we need to join the lines by space?
+			if len(trailing_breaks) == 0 {
+				s = append(s, ' ')
+			}
+		} else {
+			s = append(s, leading_break...)
+		}
+		leading_break = leading_break[:0]
+
+		// Append the remaining line breaks.
+		s = append(s, trailing_breaks...)
+		trailing_breaks = trailing_breaks[:0]
+
+		// Is it a leading whitespace?
+		leading_blank = is_blank(parser.buffer, parser.buffer_pos)
+
+		// Consume the current line.
+		for !is_breakz(parser.buffer, parser.buffer_pos) {
+			s = read(parser, s)
+			if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+				return false
+			}
+		}
+
+		// Consume the line break.
+		if parser.unread < 2 && !yaml_parser_update_buffer(parser, 2) {
+			return false
+		}
+
+		leading_break = read_line(parser, leading_break)
+
+		// Eat the following indentation spaces and line breaks.
+		if !yaml_parser_scan_block_scalar_breaks(parser, &indent, &trailing_breaks, start_mark, &end_mark) {
+			return false
+		}
+	}
+
+	// Chomp the tail.
+	if chomping != -1 {
+		s = append(s, leading_break...)
+	}
+	if chomping == 1 {
+		s = append(s, trailing_breaks...)
+	}
+
+	// Create a token.
+	*token = yaml_token_t{
+		typ:        yaml_SCALAR_TOKEN,
+		start_mark: start_mark,
+		end_mark:   end_mark,
+		value:      s,
+		style:      yaml_LITERAL_SCALAR_STYLE,
+	}
+	if !literal {
+		token.style = yaml_FOLDED_SCALAR_STYLE
+	}
+	return true
+}
+
+// Scan indentation spaces and line breaks for a block scalar.  Determine the
+// indentation level if needed.
+func yaml_parser_scan_block_scalar_breaks(parser *yaml_parser_t, indent *int, breaks *[]byte, start_mark yaml_mark_t, end_mark *yaml_mark_t) bool {
+	*end_mark = parser.mark
+
+	// Eat the indentation spaces and line breaks.
+	max_indent := 0
+	for {
+		// Eat the indentation spaces.
+		if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+			return false
+		}
+		for (*indent == 0 || parser.mark.column < *indent) && is_space(parser.buffer, parser.buffer_pos) {
+			skip(parser)
+			if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+				return false
+			}
+		}
+		if parser.mark.column > max_indent {
+			max_indent = parser.mark.column
+		}
+
+		// Check for a tab character messing the indentation.
+		if (*indent == 0 || parser.mark.column < *indent) && is_tab(parser.buffer, parser.buffer_pos) {
+			return yaml_parser_set_scanner_error(parser, "while scanning a block scalar",
+				start_mark, "found a tab character where an indentation space is expected")
+		}
+
+		// Have we found a non-empty line?
+		if !is_break(parser.buffer, parser.buffer_pos) {
+			break
+		}
+
+		// Consume the line break.
+		if parser.unread < 2 && !yaml_parser_update_buffer(parser, 2) {
+			return false
+		}
+		// [Go] Should really be returning breaks instead.
+		*breaks = read_line(parser, *breaks)
+		*end_mark = parser.mark
+	}
+
+	// Determine the indentation level if needed.
+	if *indent == 0 {
+		*indent = max_indent
+		if *indent < parser.indent+1 {
+			*indent = parser.indent + 1
+		}
+		if *indent < 1 {
+			*indent = 1
+		}
+	}
+	return true
+}
+
+// Scan a quoted scalar.
+func yaml_parser_scan_flow_scalar(parser *yaml_parser_t, token *yaml_token_t, single bool) bool {
+	// Eat the left quote.
+	start_mark := parser.mark
+	skip(parser)
+
+	// Consume the content of the quoted scalar.
+	var s, leading_break, trailing_breaks, whitespaces []byte
+	for {
+		// Check that there are no document indicators at the beginning of the line.
+		if parser.unread < 4 && !yaml_parser_update_buffer(parser, 4) {
+			return false
+		}
+
+		if parser.mark.column == 0 &&
+			((parser.buffer[parser.buffer_pos+0] == '-' &&
+				parser.buffer[parser.buffer_pos+1] == '-' &&
+				parser.buffer[parser.buffer_pos+2] == '-') ||
+				(parser.buffer[parser.buffer_pos+0] == '.' &&
+					parser.buffer[parser.buffer_pos+1] == '.' &&
+					parser.buffer[parser.buffer_pos+2] == '.')) &&
+			is_blankz(parser.buffer, parser.buffer_pos+3) {
+			yaml_parser_set_scanner_error(parser, "while scanning a quoted scalar",
+				start_mark, "found unexpected document indicator")
+			return false
+		}
+
+		// Check for EOF.
+		if is_z(parser.buffer, parser.buffer_pos) {
+			yaml_parser_set_scanner_error(parser, "while scanning a quoted scalar",
+				start_mark, "found unexpected end of stream")
+			return false
+		}
+
+		// Consume non-blank characters.
+		leading_blanks := false
+		for !is_blankz(parser.buffer, parser.buffer_pos) {
+			if single && parser.buffer[parser.buffer_pos] == '\'' && parser.buffer[parser.buffer_pos+1] == '\'' {
+				// Is is an escaped single quote.
+				s = append(s, '\'')
+				skip(parser)
+				skip(parser)
+
+			} else if single && parser.buffer[parser.buffer_pos] == '\'' {
+				// It is a right single quote.
+				break
+			} else if !single && parser.buffer[parser.buffer_pos] == '"' {
+				// It is a right double quote.
+				break
+
+			} else if !single && parser.buffer[parser.buffer_pos] == '\\' && is_break(parser.buffer, parser.buffer_pos+1) {
+				// It is an escaped line break.
+				if parser.unread < 3 && !yaml_parser_update_buffer(parser, 3) {
+					return false
+				}
+				skip(parser)
+				skip_line(parser)
+				leading_blanks = true
+				break
+
+			} else if !single && parser.buffer[parser.buffer_pos] == '\\' {
+				// It is an escape sequence.
+				code_length := 0
+
+				// Check the escape character.
+				switch parser.buffer[parser.buffer_pos+1] {
+				case '0':
+					s = append(s, 0)
+				case 'a':
+					s = append(s, '\x07')
+				case 'b':
+					s = append(s, '\x08')
+				case 't', '\t':
+					s = append(s, '\x09')
+				case 'n':
+					s = append(s, '\x0A')
+				case 'v':
+					s = append(s, '\x0B')
+				case 'f':
+					s = append(s, '\x0C')
+				case 'r':
+					s = append(s, '\x0D')
+				case 'e':
+					s = append(s, '\x1B')
+				case ' ':
+					s = append(s, '\x20')
+				case '"':
+					s = append(s, '"')
+				case '\'':
+					s = append(s, '\'')
+				case '\\':
+					s = append(s, '\\')
+				case 'N': // NEL (#x85)
+					s = append(s, '\xC2')
+					s = append(s, '\x85')
+				case '_': // #xA0
+					s = append(s, '\xC2')
+					s = append(s, '\xA0')
+				case 'L': // LS (#x2028)
+					s = append(s, '\xE2')
+					s = append(s, '\x80')
+					s = append(s, '\xA8')
+				case 'P': // PS (#x2029)
+					s = append(s, '\xE2')
+					s = append(s, '\x80')
+					s = append(s, '\xA9')
+				case 'x':
+					code_length = 2
+				case 'u':
+					code_length = 4
+				case 'U':
+					code_length = 8
+				default:
+					yaml_parser_set_scanner_error(parser, "while parsing a quoted scalar",
+						start_mark, "found unknown escape character")
+					return false
+				}
+
+				skip(parser)
+				skip(parser)
+
+				// Consume an arbitrary escape code.
+				if code_length > 0 {
+					var value int
+
+					// Scan the character value.
+					if parser.unread < code_length && !yaml_parser_update_buffer(parser, code_length) {
+						return false
+					}
+					for k := 0; k < code_length; k++ {
+						if !is_hex(parser.buffer, parser.buffer_pos+k) {
+							yaml_parser_set_scanner_error(parser, "while parsing a quoted scalar",
+								start_mark, "did not find expected hexdecimal number")
+							return false
+						}
+						value = (value << 4) + as_hex(parser.buffer, parser.buffer_pos+k)
+					}
+
+					// Check the value and write the character.
+					if (value >= 0xD800 && value <= 0xDFFF) || value > 0x10FFFF {
+						yaml_parser_set_scanner_error(parser, "while parsing a quoted scalar",
+							start_mark, "found invalid Unicode character escape code")
+						return false
+					}
+					if value <= 0x7F {
+						s = append(s, byte(value))
+					} else if value <= 0x7FF {
+						s = append(s, byte(0xC0+(value>>6)))
+						s = append(s, byte(0x80+(value&0x3F)))
+					} else if value <= 0xFFFF {
+						s = append(s, byte(0xE0+(value>>12)))
+						s = append(s, byte(0x80+((value>>6)&0x3F)))
+						s = append(s, byte(0x80+(value&0x3F)))
+					} else {
+						s = append(s, byte(0xF0+(value>>18)))
+						s = append(s, byte(0x80+((value>>12)&0x3F)))
+						s = append(s, byte(0x80+((value>>6)&0x3F)))
+						s = append(s, byte(0x80+(value&0x3F)))
+					}
+
+					// Advance the pointer.
+					for k := 0; k < code_length; k++ {
+						skip(parser)
+					}
+				}
+			} else {
+				// It is a non-escaped non-blank character.
+				s = read(parser, s)
+			}
+			if parser.unread < 2 && !yaml_parser_update_buffer(parser, 2) {
+				return false
+			}
+		}
+
+		if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+			return false
+		}
+
+		// Check if we are at the end of the scalar.
+		if single {
+			if parser.buffer[parser.buffer_pos] == '\'' {
+				break
+			}
+		} else {
+			if parser.buffer[parser.buffer_pos] == '"' {
+				break
+			}
+		}
+
+		// Consume blank characters.
+		for is_blank(parser.buffer, parser.buffer_pos) || is_break(parser.buffer, parser.buffer_pos) {
+			if is_blank(parser.buffer, parser.buffer_pos) {
+				// Consume a space or a tab character.
+				if !leading_blanks {
+					whitespaces = read(parser, whitespaces)
+				} else {
+					skip(parser)
+				}
+			} else {
+				if parser.unread < 2 && !yaml_parser_update_buffer(parser, 2) {
+					return false
+				}
+
+				// Check if it is a first line break.
+				if !leading_blanks {
+					whitespaces = whitespaces[:0]
+					leading_break = read_line(parser, leading_break)
+					leading_blanks = true
+				} else {
+					trailing_breaks = read_line(parser, trailing_breaks)
+				}
+			}
+			if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+				return false
+			}
+		}
+
+		// Join the whitespaces or fold line breaks.
+		if leading_blanks {
+			// Do we need to fold line breaks?
+			if len(leading_break) > 0 && leading_break[0] == '\n' {
+				if len(trailing_breaks) == 0 {
+					s = append(s, ' ')
+				} else {
+					s = append(s, trailing_breaks...)
+				}
+			} else {
+				s = append(s, leading_break...)
+				s = append(s, trailing_breaks...)
+			}
+			trailing_breaks = trailing_breaks[:0]
+			leading_break = leading_break[:0]
+		} else {
+			s = append(s, whitespaces...)
+			whitespaces = whitespaces[:0]
+		}
+	}
+
+	// Eat the right quote.
+	skip(parser)
+	end_mark := parser.mark
+
+	// Create a token.
+	*token = yaml_token_t{
+		typ:        yaml_SCALAR_TOKEN,
+		start_mark: start_mark,
+		end_mark:   end_mark,
+		value:      s,
+		style:      yaml_SINGLE_QUOTED_SCALAR_STYLE,
+	}
+	if !single {
+		token.style = yaml_DOUBLE_QUOTED_SCALAR_STYLE
+	}
+	return true
+}
+
+// Scan a plain scalar.
+func yaml_parser_scan_plain_scalar(parser *yaml_parser_t, token *yaml_token_t) bool {
+
+	var s, leading_break, trailing_breaks, whitespaces []byte
+	var leading_blanks bool
+	var indent = parser.indent + 1
+
+	start_mark := parser.mark
+	end_mark := parser.mark
+
+	// Consume the content of the plain scalar.
+	for {
+		// Check for a document indicator.
+		if parser.unread < 4 && !yaml_parser_update_buffer(parser, 4) {
+			return false
+		}
+		if parser.mark.column == 0 &&
+			((parser.buffer[parser.buffer_pos+0] == '-' &&
+				parser.buffer[parser.buffer_pos+1] == '-' &&
+				parser.buffer[parser.buffer_pos+2] == '-') ||
+				(parser.buffer[parser.buffer_pos+0] == '.' &&
+					parser.buffer[parser.buffer_pos+1] == '.' &&
+					parser.buffer[parser.buffer_pos+2] == '.')) &&
+			is_blankz(parser.buffer, parser.buffer_pos+3) {
+			break
+		}
+
+		// Check for a comment.
+		if parser.buffer[parser.buffer_pos] == '#' {
+			break
+		}
+
+		// Consume non-blank characters.
+		for !is_blankz(parser.buffer, parser.buffer_pos) {
+
+			// Check for indicators that may end a plain scalar.
+			if (parser.buffer[parser.buffer_pos] == ':' && is_blankz(parser.buffer, parser.buffer_pos+1)) ||
+				(parser.flow_level > 0 &&
+					(parser.buffer[parser.buffer_pos] == ',' ||
+						parser.buffer[parser.buffer_pos] == '?' || parser.buffer[parser.buffer_pos] == '[' ||
+						parser.buffer[parser.buffer_pos] == ']' || parser.buffer[parser.buffer_pos] == '{' ||
+						parser.buffer[parser.buffer_pos] == '}')) {
+				break
+			}
+
+			// Check if we need to join whitespaces and breaks.
+			if leading_blanks || len(whitespaces) > 0 {
+				if leading_blanks {
+					// Do we need to fold line breaks?
+					if leading_break[0] == '\n' {
+						if len(trailing_breaks) == 0 {
+							s = append(s, ' ')
+						} else {
+							s = append(s, trailing_breaks...)
+						}
+					} else {
+						s = append(s, leading_break...)
+						s = append(s, trailing_breaks...)
+					}
+					trailing_breaks = trailing_breaks[:0]
+					leading_break = leading_break[:0]
+					leading_blanks = false
+				} else {
+					s = append(s, whitespaces...)
+					whitespaces = whitespaces[:0]
+				}
+			}
+
+			// Copy the character.
+			s = read(parser, s)
+
+			end_mark = parser.mark
+			if parser.unread < 2 && !yaml_parser_update_buffer(parser, 2) {
+				return false
+			}
+		}
+
+		// Is it the end?
+		if !(is_blank(parser.buffer, parser.buffer_pos) || is_break(parser.buffer, parser.buffer_pos)) {
+			break
+		}
+
+		// Consume blank characters.
+		if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+			return false
+		}
+
+		for is_blank(parser.buffer, parser.buffer_pos) || is_break(parser.buffer, parser.buffer_pos) {
+			if is_blank(parser.buffer, parser.buffer_pos) {
+
+				// Check for tab characters that abuse indentation.
+				if leading_blanks && parser.mark.column < indent && is_tab(parser.buffer, parser.buffer_pos) {
+					yaml_parser_set_scanner_error(parser, "while scanning a plain scalar",
+						start_mark, "found a tab character that violates indentation")
+					return false
+				}
+
+				// Consume a space or a tab character.
+				if !leading_blanks {
+					whitespaces = read(parser, whitespaces)
+				} else {
+					skip(parser)
+				}
+			} else {
+				if parser.unread < 2 && !yaml_parser_update_buffer(parser, 2) {
+					return false
+				}
+
+				// Check if it is a first line break.
+				if !leading_blanks {
+					whitespaces = whitespaces[:0]
+					leading_break = read_line(parser, leading_break)
+					leading_blanks = true
+				} else {
+					trailing_breaks = read_line(parser, trailing_breaks)
+				}
+			}
+			if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+				return false
+			}
+		}
+
+		// Check indentation level.
+		if parser.flow_level == 0 && parser.mark.column < indent {
+			break
+		}
+	}
+
+	// Create a token.
+	*token = yaml_token_t{
+		typ:        yaml_SCALAR_TOKEN,
+		start_mark: start_mark,
+		end_mark:   end_mark,
+		value:      s,
+		style:      yaml_PLAIN_SCALAR_STYLE,
+	}
+
+	// Note that we change the 'simple_key_allowed' flag.
+	if leading_blanks {
+		parser.simple_key_allowed = true
+	}
+	return true
+}
+
+func yaml_parser_scan_line_comment(parser *yaml_parser_t, token_mark yaml_mark_t) bool {
+	if parser.newlines > 0 {
+		return true
+	}
+
+	var start_mark yaml_mark_t
+	var text []byte
+
+	for peek := 0; peek < 512; peek++ {
+		if parser.unread < peek+1 && !yaml_parser_update_buffer(parser, peek+1) {
+			break
+		}
+		if is_blank(parser.buffer, parser.buffer_pos+peek) {
+			continue
+		}
+		if parser.buffer[parser.buffer_pos+peek] == '#' {
+			seen := parser.mark.index+peek
+			for {
+				if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+					return false
+				}
+				if is_breakz(parser.buffer, parser.buffer_pos) {
+					if parser.mark.index >= seen {
+						break
+					}
+					if parser.unread < 2 && !yaml_parser_update_buffer(parser, 2) {
+						return false
+					}
+					skip_line(parser)
+				} else if parser.mark.index >= seen {
+					if len(text) == 0 {
+						start_mark = parser.mark
+					}
+					text = read(parser, text)
+				} else {
+					skip(parser)
+				}
+			}
+		}
+		break
+	}
+	if len(text) > 0 {
+		parser.comments = append(parser.comments, yaml_comment_t{
+			token_mark: token_mark,
+			start_mark: start_mark,
+			line: text,
+		})
+	}
+	return true
+}
+
+func yaml_parser_scan_comments(parser *yaml_parser_t, scan_mark yaml_mark_t) bool {
+	token := parser.tokens[len(parser.tokens)-1]
+
+	if token.typ == yaml_FLOW_ENTRY_TOKEN && len(parser.tokens) > 1 {
+		token = parser.tokens[len(parser.tokens)-2]
+	}
+
+	var token_mark = token.start_mark
+	var start_mark yaml_mark_t
+	var next_indent = parser.indent
+	if next_indent < 0 {
+		next_indent = 0
+	}
+
+	var recent_empty = false
+	var first_empty = parser.newlines <= 1
+
+	var line = parser.mark.line
+	var column = parser.mark.column
+
+	var text []byte
+
+	// The foot line is the place where a comment must start to
+	// still be considered as a foot of the prior content.
+	// If there's some content in the currently parsed line, then
+	// the foot is the line below it.
+	var foot_line = -1
+	if scan_mark.line > 0 {
+		foot_line = parser.mark.line-parser.newlines+1
+		if parser.newlines == 0 && parser.mark.column > 1 {
+			foot_line++
+		}
+	}
+
+	var peek = 0
+	for ; peek < 512; peek++ {
+		if parser.unread < peek+1 && !yaml_parser_update_buffer(parser, peek+1) {
+			break
+		}
+		column++
+		if is_blank(parser.buffer, parser.buffer_pos+peek) {
+			continue
+		}
+		c := parser.buffer[parser.buffer_pos+peek]
+		var close_flow = parser.flow_level > 0 && (c == ']' || c == '}')
+		if close_flow || is_breakz(parser.buffer, parser.buffer_pos+peek) {
+			// Got line break or terminator.
+			if close_flow || !recent_empty {
+				if close_flow || first_empty && (start_mark.line == foot_line && token.typ != yaml_VALUE_TOKEN || start_mark.column-1 < next_indent) {
+					// This is the first empty line and there were no empty lines before,
+					// so this initial part of the comment is a foot of the prior token
+					// instead of being a head for the following one. Split it up.
+					// Alternatively, this might also be the last comment inside a flow
+					// scope, so it must be a footer.
+					if len(text) > 0 {
+						if start_mark.column-1 < next_indent {
+							// If dedented it's unrelated to the prior token.
+							token_mark = start_mark
+						}
+						parser.comments = append(parser.comments, yaml_comment_t{
+							scan_mark:  scan_mark,
+							token_mark: token_mark,
+							start_mark: start_mark,
+							end_mark:   yaml_mark_t{parser.mark.index + peek, line, column},
+							foot:       text,
+						})
+						scan_mark = yaml_mark_t{parser.mark.index + peek, line, column}
+						token_mark = scan_mark
+						text = nil
+					}
+				} else {
+					if len(text) > 0 && parser.buffer[parser.buffer_pos+peek] != 0 {
+						text = append(text, '\n')
+					}
+				}
+			}
+			if !is_break(parser.buffer, parser.buffer_pos+peek) {
+				break
+			}
+			first_empty = false
+			recent_empty = true
+			column = 0
+			line++
+			continue
+		}
+
+		if len(text) > 0 && (close_flow || column-1 < next_indent && column != start_mark.column) {
+			// The comment at the different indentation is a foot of the
+			// preceding data rather than a head of the upcoming one.
+			parser.comments = append(parser.comments, yaml_comment_t{
+				scan_mark:  scan_mark,
+				token_mark: token_mark,
+				start_mark: start_mark,
+				end_mark:   yaml_mark_t{parser.mark.index + peek, line, column},
+				foot:       text,
+			})
+			scan_mark = yaml_mark_t{parser.mark.index + peek, line, column}
+			token_mark = scan_mark
+			text = nil
+		}
+
+		if parser.buffer[parser.buffer_pos+peek] != '#' {
+			break
+		}
+
+		if len(text) == 0 {
+			start_mark = yaml_mark_t{parser.mark.index + peek, line, column}
+		} else {
+			text = append(text, '\n')
+		}
+
+		recent_empty = false
+
+		// Consume until after the consumed comment line.
+		seen := parser.mark.index+peek
+		for {
+			if parser.unread < 1 && !yaml_parser_update_buffer(parser, 1) {
+				return false
+			}
+			if is_breakz(parser.buffer, parser.buffer_pos) {
+				if parser.mark.index >= seen {
+					break
+				}
+				if parser.unread < 2 && !yaml_parser_update_buffer(parser, 2) {
+					return false
+				}
+				skip_line(parser)
+			} else if parser.mark.index >= seen {
+				text = read(parser, text)
+			} else {
+				skip(parser)
+			}
+		}
+
+		peek = 0
+		column = 0
+		line = parser.mark.line
+		next_indent = parser.indent
+		if next_indent < 0 {
+			next_indent = 0
+		}
+	}
+
+	if len(text) > 0 {
+		parser.comments = append(parser.comments, yaml_comment_t{
+			scan_mark:  scan_mark,
+			token_mark: start_mark,
+			start_mark: start_mark,
+			end_mark:   yaml_mark_t{parser.mark.index + peek - 1, line, column},
+			head:       text,
+		})
+	}
+	return true
+}
diff --git a/vendor/gopkg.in/yaml.v3/sorter.go b/vendor/gopkg.in/yaml.v3/sorter.go
new file mode 100644
index 000000000000..9210ece7e972
--- /dev/null
+++ b/vendor/gopkg.in/yaml.v3/sorter.go
@@ -0,0 +1,134 @@
+//
+// Copyright (c) 2011-2019 Canonical Ltd
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package yaml
+
+import (
+	"reflect"
+	"unicode"
+)
+
+type keyList []reflect.Value
+
+func (l keyList) Len() int      { return len(l) }
+func (l keyList) Swap(i, j int) { l[i], l[j] = l[j], l[i] }
+func (l keyList) Less(i, j int) bool {
+	a := l[i]
+	b := l[j]
+	ak := a.Kind()
+	bk := b.Kind()
+	for (ak == reflect.Interface || ak == reflect.Ptr) && !a.IsNil() {
+		a = a.Elem()
+		ak = a.Kind()
+	}
+	for (bk == reflect.Interface || bk == reflect.Ptr) && !b.IsNil() {
+		b = b.Elem()
+		bk = b.Kind()
+	}
+	af, aok := keyFloat(a)
+	bf, bok := keyFloat(b)
+	if aok && bok {
+		if af != bf {
+			return af < bf
+		}
+		if ak != bk {
+			return ak < bk
+		}
+		return numLess(a, b)
+	}
+	if ak != reflect.String || bk != reflect.String {
+		return ak < bk
+	}
+	ar, br := []rune(a.String()), []rune(b.String())
+	digits := false
+	for i := 0; i < len(ar) && i < len(br); i++ {
+		if ar[i] == br[i] {
+			digits = unicode.IsDigit(ar[i])
+			continue
+		}
+		al := unicode.IsLetter(ar[i])
+		bl := unicode.IsLetter(br[i])
+		if al && bl {
+			return ar[i] < br[i]
+		}
+		if al || bl {
+			if digits {
+				return al
+			} else {
+				return bl
+			}
+		}
+		var ai, bi int
+		var an, bn int64
+		if ar[i] == '0' || br[i] == '0' {
+			for j := i - 1; j >= 0 && unicode.IsDigit(ar[j]); j-- {
+				if ar[j] != '0' {
+					an = 1
+					bn = 1
+					break
+				}
+			}
+		}
+		for ai = i; ai < len(ar) && unicode.IsDigit(ar[ai]); ai++ {
+			an = an*10 + int64(ar[ai]-'0')
+		}
+		for bi = i; bi < len(br) && unicode.IsDigit(br[bi]); bi++ {
+			bn = bn*10 + int64(br[bi]-'0')
+		}
+		if an != bn {
+			return an < bn
+		}
+		if ai != bi {
+			return ai < bi
+		}
+		return ar[i] < br[i]
+	}
+	return len(ar) < len(br)
+}
+
+// keyFloat returns a float value for v if it is a number/bool
+// and whether it is a number/bool or not.
+func keyFloat(v reflect.Value) (f float64, ok bool) {
+	switch v.Kind() {
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		return float64(v.Int()), true
+	case reflect.Float32, reflect.Float64:
+		return v.Float(), true
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+		return float64(v.Uint()), true
+	case reflect.Bool:
+		if v.Bool() {
+			return 1, true
+		}
+		return 0, true
+	}
+	return 0, false
+}
+
+// numLess returns whether a < b.
+// a and b must necessarily have the same kind.
+func numLess(a, b reflect.Value) bool {
+	switch a.Kind() {
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		return a.Int() < b.Int()
+	case reflect.Float32, reflect.Float64:
+		return a.Float() < b.Float()
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+		return a.Uint() < b.Uint()
+	case reflect.Bool:
+		return !a.Bool() && b.Bool()
+	}
+	panic("not a number")
+}
diff --git a/vendor/gopkg.in/yaml.v3/writerc.go b/vendor/gopkg.in/yaml.v3/writerc.go
new file mode 100644
index 000000000000..b8a116bf9a22
--- /dev/null
+++ b/vendor/gopkg.in/yaml.v3/writerc.go
@@ -0,0 +1,48 @@
+// 
+// Copyright (c) 2011-2019 Canonical Ltd
+// Copyright (c) 2006-2010 Kirill Simonov
+// 
+// Permission is hereby granted, free of charge, to any person obtaining a copy of
+// this software and associated documentation files (the "Software"), to deal in
+// the Software without restriction, including without limitation the rights to
+// use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+// of the Software, and to permit persons to whom the Software is furnished to do
+// so, subject to the following conditions:
+// 
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+// 
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+package yaml
+
+// Set the writer error and return false.
+func yaml_emitter_set_writer_error(emitter *yaml_emitter_t, problem string) bool {
+	emitter.error = yaml_WRITER_ERROR
+	emitter.problem = problem
+	return false
+}
+
+// Flush the output buffer.
+func yaml_emitter_flush(emitter *yaml_emitter_t) bool {
+	if emitter.write_handler == nil {
+		panic("write handler not set")
+	}
+
+	// Check if the buffer is empty.
+	if emitter.buffer_pos == 0 {
+		return true
+	}
+
+	if err := emitter.write_handler(emitter, emitter.buffer[:emitter.buffer_pos]); err != nil {
+		return yaml_emitter_set_writer_error(emitter, "write error: "+err.Error())
+	}
+	emitter.buffer_pos = 0
+	return true
+}
diff --git a/vendor/gopkg.in/yaml.v3/yaml.go b/vendor/gopkg.in/yaml.v3/yaml.go
new file mode 100644
index 000000000000..8cec6da48d3e
--- /dev/null
+++ b/vendor/gopkg.in/yaml.v3/yaml.go
@@ -0,0 +1,698 @@
+//
+// Copyright (c) 2011-2019 Canonical Ltd
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package yaml implements YAML support for the Go language.
+//
+// Source code and other details for the project are available at GitHub:
+//
+//   https://github.com/go-yaml/yaml
+//
+package yaml
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"reflect"
+	"strings"
+	"sync"
+	"unicode/utf8"
+)
+
+// The Unmarshaler interface may be implemented by types to customize their
+// behavior when being unmarshaled from a YAML document.
+type Unmarshaler interface {
+	UnmarshalYAML(value *Node) error
+}
+
+type obsoleteUnmarshaler interface {
+	UnmarshalYAML(unmarshal func(interface{}) error) error
+}
+
+// The Marshaler interface may be implemented by types to customize their
+// behavior when being marshaled into a YAML document. The returned value
+// is marshaled in place of the original value implementing Marshaler.
+//
+// If an error is returned by MarshalYAML, the marshaling procedure stops
+// and returns with the provided error.
+type Marshaler interface {
+	MarshalYAML() (interface{}, error)
+}
+
+// Unmarshal decodes the first document found within the in byte slice
+// and assigns decoded values into the out value.
+//
+// Maps and pointers (to a struct, string, int, etc) are accepted as out
+// values. If an internal pointer within a struct is not initialized,
+// the yaml package will initialize it if necessary for unmarshalling
+// the provided data. The out parameter must not be nil.
+//
+// The type of the decoded values should be compatible with the respective
+// values in out. If one or more values cannot be decoded due to a type
+// mismatches, decoding continues partially until the end of the YAML
+// content, and a *yaml.TypeError is returned with details for all
+// missed values.
+//
+// Struct fields are only unmarshalled if they are exported (have an
+// upper case first letter), and are unmarshalled using the field name
+// lowercased as the default key. Custom keys may be defined via the
+// "yaml" name in the field tag: the content preceding the first comma
+// is used as the key, and the following comma-separated options are
+// used to tweak the marshalling process (see Marshal).
+// Conflicting names result in a runtime error.
+//
+// For example:
+//
+//     type T struct {
+//         F int `yaml:"a,omitempty"`
+//         B int
+//     }
+//     var t T
+//     yaml.Unmarshal([]byte("a: 1\nb: 2"), &t)
+//
+// See the documentation of Marshal for the format of tags and a list of
+// supported tag options.
+//
+func Unmarshal(in []byte, out interface{}) (err error) {
+	return unmarshal(in, out, false)
+}
+
+// A Decoder reads and decodes YAML values from an input stream.
+type Decoder struct {
+	parser      *parser
+	knownFields bool
+}
+
+// NewDecoder returns a new decoder that reads from r.
+//
+// The decoder introduces its own buffering and may read
+// data from r beyond the YAML values requested.
+func NewDecoder(r io.Reader) *Decoder {
+	return &Decoder{
+		parser: newParserFromReader(r),
+	}
+}
+
+// KnownFields ensures that the keys in decoded mappings to
+// exist as fields in the struct being decoded into.
+func (dec *Decoder) KnownFields(enable bool) {
+	dec.knownFields = enable
+}
+
+// Decode reads the next YAML-encoded value from its input
+// and stores it in the value pointed to by v.
+//
+// See the documentation for Unmarshal for details about the
+// conversion of YAML into a Go value.
+func (dec *Decoder) Decode(v interface{}) (err error) {
+	d := newDecoder()
+	d.knownFields = dec.knownFields
+	defer handleErr(&err)
+	node := dec.parser.parse()
+	if node == nil {
+		return io.EOF
+	}
+	out := reflect.ValueOf(v)
+	if out.Kind() == reflect.Ptr && !out.IsNil() {
+		out = out.Elem()
+	}
+	d.unmarshal(node, out)
+	if len(d.terrors) > 0 {
+		return &TypeError{d.terrors}
+	}
+	return nil
+}
+
+// Decode decodes the node and stores its data into the value pointed to by v.
+//
+// See the documentation for Unmarshal for details about the
+// conversion of YAML into a Go value.
+func (n *Node) Decode(v interface{}) (err error) {
+	d := newDecoder()
+	defer handleErr(&err)
+	out := reflect.ValueOf(v)
+	if out.Kind() == reflect.Ptr && !out.IsNil() {
+		out = out.Elem()
+	}
+	d.unmarshal(n, out)
+	if len(d.terrors) > 0 {
+		return &TypeError{d.terrors}
+	}
+	return nil
+}
+
+func unmarshal(in []byte, out interface{}, strict bool) (err error) {
+	defer handleErr(&err)
+	d := newDecoder()
+	p := newParser(in)
+	defer p.destroy()
+	node := p.parse()
+	if node != nil {
+		v := reflect.ValueOf(out)
+		if v.Kind() == reflect.Ptr && !v.IsNil() {
+			v = v.Elem()
+		}
+		d.unmarshal(node, v)
+	}
+	if len(d.terrors) > 0 {
+		return &TypeError{d.terrors}
+	}
+	return nil
+}
+
+// Marshal serializes the value provided into a YAML document. The structure
+// of the generated document will reflect the structure of the value itself.
+// Maps and pointers (to struct, string, int, etc) are accepted as the in value.
+//
+// Struct fields are only marshalled if they are exported (have an upper case
+// first letter), and are marshalled using the field name lowercased as the
+// default key. Custom keys may be defined via the "yaml" name in the field
+// tag: the content preceding the first comma is used as the key, and the
+// following comma-separated options are used to tweak the marshalling process.
+// Conflicting names result in a runtime error.
+//
+// The field tag format accepted is:
+//
+//     `(...) yaml:"[<key>][,<flag1>[,<flag2>]]" (...)`
+//
+// The following flags are currently supported:
+//
+//     omitempty    Only include the field if it's not set to the zero
+//                  value for the type or to empty slices or maps.
+//                  Zero valued structs will be omitted if all their public
+//                  fields are zero, unless they implement an IsZero
+//                  method (see the IsZeroer interface type), in which
+//                  case the field will be excluded if IsZero returns true.
+//
+//     flow         Marshal using a flow style (useful for structs,
+//                  sequences and maps).
+//
+//     inline       Inline the field, which must be a struct or a map,
+//                  causing all of its fields or keys to be processed as if
+//                  they were part of the outer struct. For maps, keys must
+//                  not conflict with the yaml keys of other struct fields.
+//
+// In addition, if the key is "-", the field is ignored.
+//
+// For example:
+//
+//     type T struct {
+//         F int `yaml:"a,omitempty"`
+//         B int
+//     }
+//     yaml.Marshal(&T{B: 2}) // Returns "b: 2\n"
+//     yaml.Marshal(&T{F: 1}} // Returns "a: 1\nb: 0\n"
+//
+func Marshal(in interface{}) (out []byte, err error) {
+	defer handleErr(&err)
+	e := newEncoder()
+	defer e.destroy()
+	e.marshalDoc("", reflect.ValueOf(in))
+	e.finish()
+	out = e.out
+	return
+}
+
+// An Encoder writes YAML values to an output stream.
+type Encoder struct {
+	encoder *encoder
+}
+
+// NewEncoder returns a new encoder that writes to w.
+// The Encoder should be closed after use to flush all data
+// to w.
+func NewEncoder(w io.Writer) *Encoder {
+	return &Encoder{
+		encoder: newEncoderWithWriter(w),
+	}
+}
+
+// Encode writes the YAML encoding of v to the stream.
+// If multiple items are encoded to the stream, the
+// second and subsequent document will be preceded
+// with a "---" document separator, but the first will not.
+//
+// See the documentation for Marshal for details about the conversion of Go
+// values to YAML.
+func (e *Encoder) Encode(v interface{}) (err error) {
+	defer handleErr(&err)
+	e.encoder.marshalDoc("", reflect.ValueOf(v))
+	return nil
+}
+
+// Encode encodes value v and stores its representation in n.
+//
+// See the documentation for Marshal for details about the
+// conversion of Go values into YAML.
+func (n *Node) Encode(v interface{}) (err error) {
+	defer handleErr(&err)
+	e := newEncoder()
+	defer e.destroy()
+	e.marshalDoc("", reflect.ValueOf(v))
+	e.finish()
+	p := newParser(e.out)
+	p.textless = true
+	defer p.destroy()
+	doc := p.parse()
+	*n = *doc.Content[0]
+	return nil
+}
+
+// SetIndent changes the used indentation used when encoding.
+func (e *Encoder) SetIndent(spaces int) {
+	if spaces < 0 {
+		panic("yaml: cannot indent to a negative number of spaces")
+	}
+	e.encoder.indent = spaces
+}
+
+// Close closes the encoder by writing any remaining data.
+// It does not write a stream terminating string "...".
+func (e *Encoder) Close() (err error) {
+	defer handleErr(&err)
+	e.encoder.finish()
+	return nil
+}
+
+func handleErr(err *error) {
+	if v := recover(); v != nil {
+		if e, ok := v.(yamlError); ok {
+			*err = e.err
+		} else {
+			panic(v)
+		}
+	}
+}
+
+type yamlError struct {
+	err error
+}
+
+func fail(err error) {
+	panic(yamlError{err})
+}
+
+func failf(format string, args ...interface{}) {
+	panic(yamlError{fmt.Errorf("yaml: "+format, args...)})
+}
+
+// A TypeError is returned by Unmarshal when one or more fields in
+// the YAML document cannot be properly decoded into the requested
+// types. When this error is returned, the value is still
+// unmarshaled partially.
+type TypeError struct {
+	Errors []string
+}
+
+func (e *TypeError) Error() string {
+	return fmt.Sprintf("yaml: unmarshal errors:\n  %s", strings.Join(e.Errors, "\n  "))
+}
+
+type Kind uint32
+
+const (
+	DocumentNode Kind = 1 << iota
+	SequenceNode
+	MappingNode
+	ScalarNode
+	AliasNode
+)
+
+type Style uint32
+
+const (
+	TaggedStyle Style = 1 << iota
+	DoubleQuotedStyle
+	SingleQuotedStyle
+	LiteralStyle
+	FoldedStyle
+	FlowStyle
+)
+
+// Node represents an element in the YAML document hierarchy. While documents
+// are typically encoded and decoded into higher level types, such as structs
+// and maps, Node is an intermediate representation that allows detailed
+// control over the content being decoded or encoded.
+//
+// It's worth noting that although Node offers access into details such as
+// line numbers, colums, and comments, the content when re-encoded will not
+// have its original textual representation preserved. An effort is made to
+// render the data plesantly, and to preserve comments near the data they
+// describe, though.
+//
+// Values that make use of the Node type interact with the yaml package in the
+// same way any other type would do, by encoding and decoding yaml data
+// directly or indirectly into them.
+//
+// For example:
+//
+//     var person struct {
+//             Name    string
+//             Address yaml.Node
+//     }
+//     err := yaml.Unmarshal(data, &person)
+// 
+// Or by itself:
+//
+//     var person Node
+//     err := yaml.Unmarshal(data, &person)
+//
+type Node struct {
+	// Kind defines whether the node is a document, a mapping, a sequence,
+	// a scalar value, or an alias to another node. The specific data type of
+	// scalar nodes may be obtained via the ShortTag and LongTag methods.
+	Kind  Kind
+
+	// Style allows customizing the apperance of the node in the tree.
+	Style Style
+
+	// Tag holds the YAML tag defining the data type for the value.
+	// When decoding, this field will always be set to the resolved tag,
+	// even when it wasn't explicitly provided in the YAML content.
+	// When encoding, if this field is unset the value type will be
+	// implied from the node properties, and if it is set, it will only
+	// be serialized into the representation if TaggedStyle is used or
+	// the implicit tag diverges from the provided one.
+	Tag string
+
+	// Value holds the unescaped and unquoted represenation of the value.
+	Value string
+
+	// Anchor holds the anchor name for this node, which allows aliases to point to it.
+	Anchor string
+
+	// Alias holds the node that this alias points to. Only valid when Kind is AliasNode.
+	Alias *Node
+
+	// Content holds contained nodes for documents, mappings, and sequences.
+	Content []*Node
+
+	// HeadComment holds any comments in the lines preceding the node and
+	// not separated by an empty line.
+	HeadComment string
+
+	// LineComment holds any comments at the end of the line where the node is in.
+	LineComment string
+
+	// FootComment holds any comments following the node and before empty lines.
+	FootComment string
+
+	// Line and Column hold the node position in the decoded YAML text.
+	// These fields are not respected when encoding the node.
+	Line   int
+	Column int
+}
+
+// IsZero returns whether the node has all of its fields unset.
+func (n *Node) IsZero() bool {
+	return n.Kind == 0 && n.Style == 0 && n.Tag == "" && n.Value == "" && n.Anchor == "" && n.Alias == nil && n.Content == nil &&
+		n.HeadComment == "" && n.LineComment == "" && n.FootComment == "" && n.Line == 0 && n.Column == 0
+}
+
+
+// LongTag returns the long form of the tag that indicates the data type for
+// the node. If the Tag field isn't explicitly defined, one will be computed
+// based on the node properties.
+func (n *Node) LongTag() string {
+	return longTag(n.ShortTag())
+}
+
+// ShortTag returns the short form of the YAML tag that indicates data type for
+// the node. If the Tag field isn't explicitly defined, one will be computed
+// based on the node properties.
+func (n *Node) ShortTag() string {
+	if n.indicatedString() {
+		return strTag
+	}
+	if n.Tag == "" || n.Tag == "!" {
+		switch n.Kind {
+		case MappingNode:
+			return mapTag
+		case SequenceNode:
+			return seqTag
+		case AliasNode:
+			if n.Alias != nil {
+				return n.Alias.ShortTag()
+			}
+		case ScalarNode:
+			tag, _ := resolve("", n.Value)
+			return tag
+		case 0:
+			// Special case to make the zero value convenient.
+			if n.IsZero() {
+				return nullTag
+			}
+		}
+		return ""
+	}
+	return shortTag(n.Tag)
+}
+
+func (n *Node) indicatedString() bool {
+	return n.Kind == ScalarNode &&
+		(shortTag(n.Tag) == strTag ||
+			(n.Tag == "" || n.Tag == "!") && n.Style&(SingleQuotedStyle|DoubleQuotedStyle|LiteralStyle|FoldedStyle) != 0)
+}
+
+// SetString is a convenience function that sets the node to a string value
+// and defines its style in a pleasant way depending on its content.
+func (n *Node) SetString(s string) {
+	n.Kind = ScalarNode
+	if utf8.ValidString(s) {
+		n.Value = s
+		n.Tag = strTag
+	} else {
+		n.Value = encodeBase64(s)
+		n.Tag = binaryTag
+	}
+	if strings.Contains(n.Value, "\n") {
+		n.Style = LiteralStyle
+	}
+}
+
+// --------------------------------------------------------------------------
+// Maintain a mapping of keys to structure field indexes
+
+// The code in this section was copied from mgo/bson.
+
+// structInfo holds details for the serialization of fields of
+// a given struct.
+type structInfo struct {
+	FieldsMap  map[string]fieldInfo
+	FieldsList []fieldInfo
+
+	// InlineMap is the number of the field in the struct that
+	// contains an ,inline map, or -1 if there's none.
+	InlineMap int
+
+	// InlineUnmarshalers holds indexes to inlined fields that
+	// contain unmarshaler values.
+	InlineUnmarshalers [][]int
+}
+
+type fieldInfo struct {
+	Key       string
+	Num       int
+	OmitEmpty bool
+	Flow      bool
+	// Id holds the unique field identifier, so we can cheaply
+	// check for field duplicates without maintaining an extra map.
+	Id int
+
+	// Inline holds the field index if the field is part of an inlined struct.
+	Inline []int
+}
+
+var structMap = make(map[reflect.Type]*structInfo)
+var fieldMapMutex sync.RWMutex
+var unmarshalerType reflect.Type
+
+func init() {
+	var v Unmarshaler
+	unmarshalerType = reflect.ValueOf(&v).Elem().Type()
+}
+
+func getStructInfo(st reflect.Type) (*structInfo, error) {
+	fieldMapMutex.RLock()
+	sinfo, found := structMap[st]
+	fieldMapMutex.RUnlock()
+	if found {
+		return sinfo, nil
+	}
+
+	n := st.NumField()
+	fieldsMap := make(map[string]fieldInfo)
+	fieldsList := make([]fieldInfo, 0, n)
+	inlineMap := -1
+	inlineUnmarshalers := [][]int(nil)
+	for i := 0; i != n; i++ {
+		field := st.Field(i)
+		if field.PkgPath != "" && !field.Anonymous {
+			continue // Private field
+		}
+
+		info := fieldInfo{Num: i}
+
+		tag := field.Tag.Get("yaml")
+		if tag == "" && strings.Index(string(field.Tag), ":") < 0 {
+			tag = string(field.Tag)
+		}
+		if tag == "-" {
+			continue
+		}
+
+		inline := false
+		fields := strings.Split(tag, ",")
+		if len(fields) > 1 {
+			for _, flag := range fields[1:] {
+				switch flag {
+				case "omitempty":
+					info.OmitEmpty = true
+				case "flow":
+					info.Flow = true
+				case "inline":
+					inline = true
+				default:
+					return nil, errors.New(fmt.Sprintf("unsupported flag %q in tag %q of type %s", flag, tag, st))
+				}
+			}
+			tag = fields[0]
+		}
+
+		if inline {
+			switch field.Type.Kind() {
+			case reflect.Map:
+				if inlineMap >= 0 {
+					return nil, errors.New("multiple ,inline maps in struct " + st.String())
+				}
+				if field.Type.Key() != reflect.TypeOf("") {
+					return nil, errors.New("option ,inline needs a map with string keys in struct " + st.String())
+				}
+				inlineMap = info.Num
+			case reflect.Struct, reflect.Ptr:
+				ftype := field.Type
+				for ftype.Kind() == reflect.Ptr {
+					ftype = ftype.Elem()
+				}
+				if ftype.Kind() != reflect.Struct {
+					return nil, errors.New("option ,inline may only be used on a struct or map field")
+				}
+				if reflect.PtrTo(ftype).Implements(unmarshalerType) {
+					inlineUnmarshalers = append(inlineUnmarshalers, []int{i})
+				} else {
+					sinfo, err := getStructInfo(ftype)
+					if err != nil {
+						return nil, err
+					}
+					for _, index := range sinfo.InlineUnmarshalers {
+						inlineUnmarshalers = append(inlineUnmarshalers, append([]int{i}, index...))
+					}
+					for _, finfo := range sinfo.FieldsList {
+						if _, found := fieldsMap[finfo.Key]; found {
+							msg := "duplicated key '" + finfo.Key + "' in struct " + st.String()
+							return nil, errors.New(msg)
+						}
+						if finfo.Inline == nil {
+							finfo.Inline = []int{i, finfo.Num}
+						} else {
+							finfo.Inline = append([]int{i}, finfo.Inline...)
+						}
+						finfo.Id = len(fieldsList)
+						fieldsMap[finfo.Key] = finfo
+						fieldsList = append(fieldsList, finfo)
+					}
+				}
+			default:
+				return nil, errors.New("option ,inline may only be used on a struct or map field")
+			}
+			continue
+		}
+
+		if tag != "" {
+			info.Key = tag
+		} else {
+			info.Key = strings.ToLower(field.Name)
+		}
+
+		if _, found = fieldsMap[info.Key]; found {
+			msg := "duplicated key '" + info.Key + "' in struct " + st.String()
+			return nil, errors.New(msg)
+		}
+
+		info.Id = len(fieldsList)
+		fieldsList = append(fieldsList, info)
+		fieldsMap[info.Key] = info
+	}
+
+	sinfo = &structInfo{
+		FieldsMap:          fieldsMap,
+		FieldsList:         fieldsList,
+		InlineMap:          inlineMap,
+		InlineUnmarshalers: inlineUnmarshalers,
+	}
+
+	fieldMapMutex.Lock()
+	structMap[st] = sinfo
+	fieldMapMutex.Unlock()
+	return sinfo, nil
+}
+
+// IsZeroer is used to check whether an object is zero to
+// determine whether it should be omitted when marshaling
+// with the omitempty flag. One notable implementation
+// is time.Time.
+type IsZeroer interface {
+	IsZero() bool
+}
+
+func isZero(v reflect.Value) bool {
+	kind := v.Kind()
+	if z, ok := v.Interface().(IsZeroer); ok {
+		if (kind == reflect.Ptr || kind == reflect.Interface) && v.IsNil() {
+			return true
+		}
+		return z.IsZero()
+	}
+	switch kind {
+	case reflect.String:
+		return len(v.String()) == 0
+	case reflect.Interface, reflect.Ptr:
+		return v.IsNil()
+	case reflect.Slice:
+		return v.Len() == 0
+	case reflect.Map:
+		return v.Len() == 0
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		return v.Int() == 0
+	case reflect.Float32, reflect.Float64:
+		return v.Float() == 0
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+		return v.Uint() == 0
+	case reflect.Bool:
+		return !v.Bool()
+	case reflect.Struct:
+		vt := v.Type()
+		for i := v.NumField() - 1; i >= 0; i-- {
+			if vt.Field(i).PkgPath != "" {
+				continue // Private field
+			}
+			if !isZero(v.Field(i)) {
+				return false
+			}
+		}
+		return true
+	}
+	return false
+}
diff --git a/vendor/gopkg.in/yaml.v3/yamlh.go b/vendor/gopkg.in/yaml.v3/yamlh.go
new file mode 100644
index 000000000000..7c6d00770619
--- /dev/null
+++ b/vendor/gopkg.in/yaml.v3/yamlh.go
@@ -0,0 +1,807 @@
+//
+// Copyright (c) 2011-2019 Canonical Ltd
+// Copyright (c) 2006-2010 Kirill Simonov
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy of
+// this software and associated documentation files (the "Software"), to deal in
+// the Software without restriction, including without limitation the rights to
+// use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+// of the Software, and to permit persons to whom the Software is furnished to do
+// so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+package yaml
+
+import (
+	"fmt"
+	"io"
+)
+
+// The version directive data.
+type yaml_version_directive_t struct {
+	major int8 // The major version number.
+	minor int8 // The minor version number.
+}
+
+// The tag directive data.
+type yaml_tag_directive_t struct {
+	handle []byte // The tag handle.
+	prefix []byte // The tag prefix.
+}
+
+type yaml_encoding_t int
+
+// The stream encoding.
+const (
+	// Let the parser choose the encoding.
+	yaml_ANY_ENCODING yaml_encoding_t = iota
+
+	yaml_UTF8_ENCODING    // The default UTF-8 encoding.
+	yaml_UTF16LE_ENCODING // The UTF-16-LE encoding with BOM.
+	yaml_UTF16BE_ENCODING // The UTF-16-BE encoding with BOM.
+)
+
+type yaml_break_t int
+
+// Line break types.
+const (
+	// Let the parser choose the break type.
+	yaml_ANY_BREAK yaml_break_t = iota
+
+	yaml_CR_BREAK   // Use CR for line breaks (Mac style).
+	yaml_LN_BREAK   // Use LN for line breaks (Unix style).
+	yaml_CRLN_BREAK // Use CR LN for line breaks (DOS style).
+)
+
+type yaml_error_type_t int
+
+// Many bad things could happen with the parser and emitter.
+const (
+	// No error is produced.
+	yaml_NO_ERROR yaml_error_type_t = iota
+
+	yaml_MEMORY_ERROR   // Cannot allocate or reallocate a block of memory.
+	yaml_READER_ERROR   // Cannot read or decode the input stream.
+	yaml_SCANNER_ERROR  // Cannot scan the input stream.
+	yaml_PARSER_ERROR   // Cannot parse the input stream.
+	yaml_COMPOSER_ERROR // Cannot compose a YAML document.
+	yaml_WRITER_ERROR   // Cannot write to the output stream.
+	yaml_EMITTER_ERROR  // Cannot emit a YAML stream.
+)
+
+// The pointer position.
+type yaml_mark_t struct {
+	index  int // The position index.
+	line   int // The position line.
+	column int // The position column.
+}
+
+// Node Styles
+
+type yaml_style_t int8
+
+type yaml_scalar_style_t yaml_style_t
+
+// Scalar styles.
+const (
+	// Let the emitter choose the style.
+	yaml_ANY_SCALAR_STYLE yaml_scalar_style_t = 0
+
+	yaml_PLAIN_SCALAR_STYLE         yaml_scalar_style_t = 1 << iota // The plain scalar style.
+	yaml_SINGLE_QUOTED_SCALAR_STYLE                                 // The single-quoted scalar style.
+	yaml_DOUBLE_QUOTED_SCALAR_STYLE                                 // The double-quoted scalar style.
+	yaml_LITERAL_SCALAR_STYLE                                       // The literal scalar style.
+	yaml_FOLDED_SCALAR_STYLE                                        // The folded scalar style.
+)
+
+type yaml_sequence_style_t yaml_style_t
+
+// Sequence styles.
+const (
+	// Let the emitter choose the style.
+	yaml_ANY_SEQUENCE_STYLE yaml_sequence_style_t = iota
+
+	yaml_BLOCK_SEQUENCE_STYLE // The block sequence style.
+	yaml_FLOW_SEQUENCE_STYLE  // The flow sequence style.
+)
+
+type yaml_mapping_style_t yaml_style_t
+
+// Mapping styles.
+const (
+	// Let the emitter choose the style.
+	yaml_ANY_MAPPING_STYLE yaml_mapping_style_t = iota
+
+	yaml_BLOCK_MAPPING_STYLE // The block mapping style.
+	yaml_FLOW_MAPPING_STYLE  // The flow mapping style.
+)
+
+// Tokens
+
+type yaml_token_type_t int
+
+// Token types.
+const (
+	// An empty token.
+	yaml_NO_TOKEN yaml_token_type_t = iota
+
+	yaml_STREAM_START_TOKEN // A STREAM-START token.
+	yaml_STREAM_END_TOKEN   // A STREAM-END token.
+
+	yaml_VERSION_DIRECTIVE_TOKEN // A VERSION-DIRECTIVE token.
+	yaml_TAG_DIRECTIVE_TOKEN     // A TAG-DIRECTIVE token.
+	yaml_DOCUMENT_START_TOKEN    // A DOCUMENT-START token.
+	yaml_DOCUMENT_END_TOKEN      // A DOCUMENT-END token.
+
+	yaml_BLOCK_SEQUENCE_START_TOKEN // A BLOCK-SEQUENCE-START token.
+	yaml_BLOCK_MAPPING_START_TOKEN  // A BLOCK-SEQUENCE-END token.
+	yaml_BLOCK_END_TOKEN            // A BLOCK-END token.
+
+	yaml_FLOW_SEQUENCE_START_TOKEN // A FLOW-SEQUENCE-START token.
+	yaml_FLOW_SEQUENCE_END_TOKEN   // A FLOW-SEQUENCE-END token.
+	yaml_FLOW_MAPPING_START_TOKEN  // A FLOW-MAPPING-START token.
+	yaml_FLOW_MAPPING_END_TOKEN    // A FLOW-MAPPING-END token.
+
+	yaml_BLOCK_ENTRY_TOKEN // A BLOCK-ENTRY token.
+	yaml_FLOW_ENTRY_TOKEN  // A FLOW-ENTRY token.
+	yaml_KEY_TOKEN         // A KEY token.
+	yaml_VALUE_TOKEN       // A VALUE token.
+
+	yaml_ALIAS_TOKEN  // An ALIAS token.
+	yaml_ANCHOR_TOKEN // An ANCHOR token.
+	yaml_TAG_TOKEN    // A TAG token.
+	yaml_SCALAR_TOKEN // A SCALAR token.
+)
+
+func (tt yaml_token_type_t) String() string {
+	switch tt {
+	case yaml_NO_TOKEN:
+		return "yaml_NO_TOKEN"
+	case yaml_STREAM_START_TOKEN:
+		return "yaml_STREAM_START_TOKEN"
+	case yaml_STREAM_END_TOKEN:
+		return "yaml_STREAM_END_TOKEN"
+	case yaml_VERSION_DIRECTIVE_TOKEN:
+		return "yaml_VERSION_DIRECTIVE_TOKEN"
+	case yaml_TAG_DIRECTIVE_TOKEN:
+		return "yaml_TAG_DIRECTIVE_TOKEN"
+	case yaml_DOCUMENT_START_TOKEN:
+		return "yaml_DOCUMENT_START_TOKEN"
+	case yaml_DOCUMENT_END_TOKEN:
+		return "yaml_DOCUMENT_END_TOKEN"
+	case yaml_BLOCK_SEQUENCE_START_TOKEN:
+		return "yaml_BLOCK_SEQUENCE_START_TOKEN"
+	case yaml_BLOCK_MAPPING_START_TOKEN:
+		return "yaml_BLOCK_MAPPING_START_TOKEN"
+	case yaml_BLOCK_END_TOKEN:
+		return "yaml_BLOCK_END_TOKEN"
+	case yaml_FLOW_SEQUENCE_START_TOKEN:
+		return "yaml_FLOW_SEQUENCE_START_TOKEN"
+	case yaml_FLOW_SEQUENCE_END_TOKEN:
+		return "yaml_FLOW_SEQUENCE_END_TOKEN"
+	case yaml_FLOW_MAPPING_START_TOKEN:
+		return "yaml_FLOW_MAPPING_START_TOKEN"
+	case yaml_FLOW_MAPPING_END_TOKEN:
+		return "yaml_FLOW_MAPPING_END_TOKEN"
+	case yaml_BLOCK_ENTRY_TOKEN:
+		return "yaml_BLOCK_ENTRY_TOKEN"
+	case yaml_FLOW_ENTRY_TOKEN:
+		return "yaml_FLOW_ENTRY_TOKEN"
+	case yaml_KEY_TOKEN:
+		return "yaml_KEY_TOKEN"
+	case yaml_VALUE_TOKEN:
+		return "yaml_VALUE_TOKEN"
+	case yaml_ALIAS_TOKEN:
+		return "yaml_ALIAS_TOKEN"
+	case yaml_ANCHOR_TOKEN:
+		return "yaml_ANCHOR_TOKEN"
+	case yaml_TAG_TOKEN:
+		return "yaml_TAG_TOKEN"
+	case yaml_SCALAR_TOKEN:
+		return "yaml_SCALAR_TOKEN"
+	}
+	return "<unknown token>"
+}
+
+// The token structure.
+type yaml_token_t struct {
+	// The token type.
+	typ yaml_token_type_t
+
+	// The start/end of the token.
+	start_mark, end_mark yaml_mark_t
+
+	// The stream encoding (for yaml_STREAM_START_TOKEN).
+	encoding yaml_encoding_t
+
+	// The alias/anchor/scalar value or tag/tag directive handle
+	// (for yaml_ALIAS_TOKEN, yaml_ANCHOR_TOKEN, yaml_SCALAR_TOKEN, yaml_TAG_TOKEN, yaml_TAG_DIRECTIVE_TOKEN).
+	value []byte
+
+	// The tag suffix (for yaml_TAG_TOKEN).
+	suffix []byte
+
+	// The tag directive prefix (for yaml_TAG_DIRECTIVE_TOKEN).
+	prefix []byte
+
+	// The scalar style (for yaml_SCALAR_TOKEN).
+	style yaml_scalar_style_t
+
+	// The version directive major/minor (for yaml_VERSION_DIRECTIVE_TOKEN).
+	major, minor int8
+}
+
+// Events
+
+type yaml_event_type_t int8
+
+// Event types.
+const (
+	// An empty event.
+	yaml_NO_EVENT yaml_event_type_t = iota
+
+	yaml_STREAM_START_EVENT   // A STREAM-START event.
+	yaml_STREAM_END_EVENT     // A STREAM-END event.
+	yaml_DOCUMENT_START_EVENT // A DOCUMENT-START event.
+	yaml_DOCUMENT_END_EVENT   // A DOCUMENT-END event.
+	yaml_ALIAS_EVENT          // An ALIAS event.
+	yaml_SCALAR_EVENT         // A SCALAR event.
+	yaml_SEQUENCE_START_EVENT // A SEQUENCE-START event.
+	yaml_SEQUENCE_END_EVENT   // A SEQUENCE-END event.
+	yaml_MAPPING_START_EVENT  // A MAPPING-START event.
+	yaml_MAPPING_END_EVENT    // A MAPPING-END event.
+	yaml_TAIL_COMMENT_EVENT
+)
+
+var eventStrings = []string{
+	yaml_NO_EVENT:             "none",
+	yaml_STREAM_START_EVENT:   "stream start",
+	yaml_STREAM_END_EVENT:     "stream end",
+	yaml_DOCUMENT_START_EVENT: "document start",
+	yaml_DOCUMENT_END_EVENT:   "document end",
+	yaml_ALIAS_EVENT:          "alias",
+	yaml_SCALAR_EVENT:         "scalar",
+	yaml_SEQUENCE_START_EVENT: "sequence start",
+	yaml_SEQUENCE_END_EVENT:   "sequence end",
+	yaml_MAPPING_START_EVENT:  "mapping start",
+	yaml_MAPPING_END_EVENT:    "mapping end",
+	yaml_TAIL_COMMENT_EVENT:   "tail comment",
+}
+
+func (e yaml_event_type_t) String() string {
+	if e < 0 || int(e) >= len(eventStrings) {
+		return fmt.Sprintf("unknown event %d", e)
+	}
+	return eventStrings[e]
+}
+
+// The event structure.
+type yaml_event_t struct {
+
+	// The event type.
+	typ yaml_event_type_t
+
+	// The start and end of the event.
+	start_mark, end_mark yaml_mark_t
+
+	// The document encoding (for yaml_STREAM_START_EVENT).
+	encoding yaml_encoding_t
+
+	// The version directive (for yaml_DOCUMENT_START_EVENT).
+	version_directive *yaml_version_directive_t
+
+	// The list of tag directives (for yaml_DOCUMENT_START_EVENT).
+	tag_directives []yaml_tag_directive_t
+
+	// The comments
+	head_comment []byte
+	line_comment []byte
+	foot_comment []byte
+	tail_comment []byte
+
+	// The anchor (for yaml_SCALAR_EVENT, yaml_SEQUENCE_START_EVENT, yaml_MAPPING_START_EVENT, yaml_ALIAS_EVENT).
+	anchor []byte
+
+	// The tag (for yaml_SCALAR_EVENT, yaml_SEQUENCE_START_EVENT, yaml_MAPPING_START_EVENT).
+	tag []byte
+
+	// The scalar value (for yaml_SCALAR_EVENT).
+	value []byte
+
+	// Is the document start/end indicator implicit, or the tag optional?
+	// (for yaml_DOCUMENT_START_EVENT, yaml_DOCUMENT_END_EVENT, yaml_SEQUENCE_START_EVENT, yaml_MAPPING_START_EVENT, yaml_SCALAR_EVENT).
+	implicit bool
+
+	// Is the tag optional for any non-plain style? (for yaml_SCALAR_EVENT).
+	quoted_implicit bool
+
+	// The style (for yaml_SCALAR_EVENT, yaml_SEQUENCE_START_EVENT, yaml_MAPPING_START_EVENT).
+	style yaml_style_t
+}
+
+func (e *yaml_event_t) scalar_style() yaml_scalar_style_t     { return yaml_scalar_style_t(e.style) }
+func (e *yaml_event_t) sequence_style() yaml_sequence_style_t { return yaml_sequence_style_t(e.style) }
+func (e *yaml_event_t) mapping_style() yaml_mapping_style_t   { return yaml_mapping_style_t(e.style) }
+
+// Nodes
+
+const (
+	yaml_NULL_TAG      = "tag:yaml.org,2002:null"      // The tag !!null with the only possible value: null.
+	yaml_BOOL_TAG      = "tag:yaml.org,2002:bool"      // The tag !!bool with the values: true and false.
+	yaml_STR_TAG       = "tag:yaml.org,2002:str"       // The tag !!str for string values.
+	yaml_INT_TAG       = "tag:yaml.org,2002:int"       // The tag !!int for integer values.
+	yaml_FLOAT_TAG     = "tag:yaml.org,2002:float"     // The tag !!float for float values.
+	yaml_TIMESTAMP_TAG = "tag:yaml.org,2002:timestamp" // The tag !!timestamp for date and time values.
+
+	yaml_SEQ_TAG = "tag:yaml.org,2002:seq" // The tag !!seq is used to denote sequences.
+	yaml_MAP_TAG = "tag:yaml.org,2002:map" // The tag !!map is used to denote mapping.
+
+	// Not in original libyaml.
+	yaml_BINARY_TAG = "tag:yaml.org,2002:binary"
+	yaml_MERGE_TAG  = "tag:yaml.org,2002:merge"
+
+	yaml_DEFAULT_SCALAR_TAG   = yaml_STR_TAG // The default scalar tag is !!str.
+	yaml_DEFAULT_SEQUENCE_TAG = yaml_SEQ_TAG // The default sequence tag is !!seq.
+	yaml_DEFAULT_MAPPING_TAG  = yaml_MAP_TAG // The default mapping tag is !!map.
+)
+
+type yaml_node_type_t int
+
+// Node types.
+const (
+	// An empty node.
+	yaml_NO_NODE yaml_node_type_t = iota
+
+	yaml_SCALAR_NODE   // A scalar node.
+	yaml_SEQUENCE_NODE // A sequence node.
+	yaml_MAPPING_NODE  // A mapping node.
+)
+
+// An element of a sequence node.
+type yaml_node_item_t int
+
+// An element of a mapping node.
+type yaml_node_pair_t struct {
+	key   int // The key of the element.
+	value int // The value of the element.
+}
+
+// The node structure.
+type yaml_node_t struct {
+	typ yaml_node_type_t // The node type.
+	tag []byte           // The node tag.
+
+	// The node data.
+
+	// The scalar parameters (for yaml_SCALAR_NODE).
+	scalar struct {
+		value  []byte              // The scalar value.
+		length int                 // The length of the scalar value.
+		style  yaml_scalar_style_t // The scalar style.
+	}
+
+	// The sequence parameters (for YAML_SEQUENCE_NODE).
+	sequence struct {
+		items_data []yaml_node_item_t    // The stack of sequence items.
+		style      yaml_sequence_style_t // The sequence style.
+	}
+
+	// The mapping parameters (for yaml_MAPPING_NODE).
+	mapping struct {
+		pairs_data  []yaml_node_pair_t   // The stack of mapping pairs (key, value).
+		pairs_start *yaml_node_pair_t    // The beginning of the stack.
+		pairs_end   *yaml_node_pair_t    // The end of the stack.
+		pairs_top   *yaml_node_pair_t    // The top of the stack.
+		style       yaml_mapping_style_t // The mapping style.
+	}
+
+	start_mark yaml_mark_t // The beginning of the node.
+	end_mark   yaml_mark_t // The end of the node.
+
+}
+
+// The document structure.
+type yaml_document_t struct {
+
+	// The document nodes.
+	nodes []yaml_node_t
+
+	// The version directive.
+	version_directive *yaml_version_directive_t
+
+	// The list of tag directives.
+	tag_directives_data  []yaml_tag_directive_t
+	tag_directives_start int // The beginning of the tag directives list.
+	tag_directives_end   int // The end of the tag directives list.
+
+	start_implicit int // Is the document start indicator implicit?
+	end_implicit   int // Is the document end indicator implicit?
+
+	// The start/end of the document.
+	start_mark, end_mark yaml_mark_t
+}
+
+// The prototype of a read handler.
+//
+// The read handler is called when the parser needs to read more bytes from the
+// source. The handler should write not more than size bytes to the buffer.
+// The number of written bytes should be set to the size_read variable.
+//
+// [in,out]   data        A pointer to an application data specified by
+//                        yaml_parser_set_input().
+// [out]      buffer      The buffer to write the data from the source.
+// [in]       size        The size of the buffer.
+// [out]      size_read   The actual number of bytes read from the source.
+//
+// On success, the handler should return 1.  If the handler failed,
+// the returned value should be 0. On EOF, the handler should set the
+// size_read to 0 and return 1.
+type yaml_read_handler_t func(parser *yaml_parser_t, buffer []byte) (n int, err error)
+
+// This structure holds information about a potential simple key.
+type yaml_simple_key_t struct {
+	possible     bool        // Is a simple key possible?
+	required     bool        // Is a simple key required?
+	token_number int         // The number of the token.
+	mark         yaml_mark_t // The position mark.
+}
+
+// The states of the parser.
+type yaml_parser_state_t int
+
+const (
+	yaml_PARSE_STREAM_START_STATE yaml_parser_state_t = iota
+
+	yaml_PARSE_IMPLICIT_DOCUMENT_START_STATE           // Expect the beginning of an implicit document.
+	yaml_PARSE_DOCUMENT_START_STATE                    // Expect DOCUMENT-START.
+	yaml_PARSE_DOCUMENT_CONTENT_STATE                  // Expect the content of a document.
+	yaml_PARSE_DOCUMENT_END_STATE                      // Expect DOCUMENT-END.
+	yaml_PARSE_BLOCK_NODE_STATE                        // Expect a block node.
+	yaml_PARSE_BLOCK_NODE_OR_INDENTLESS_SEQUENCE_STATE // Expect a block node or indentless sequence.
+	yaml_PARSE_FLOW_NODE_STATE                         // Expect a flow node.
+	yaml_PARSE_BLOCK_SEQUENCE_FIRST_ENTRY_STATE        // Expect the first entry of a block sequence.
+	yaml_PARSE_BLOCK_SEQUENCE_ENTRY_STATE              // Expect an entry of a block sequence.
+	yaml_PARSE_INDENTLESS_SEQUENCE_ENTRY_STATE         // Expect an entry of an indentless sequence.
+	yaml_PARSE_BLOCK_MAPPING_FIRST_KEY_STATE           // Expect the first key of a block mapping.
+	yaml_PARSE_BLOCK_MAPPING_KEY_STATE                 // Expect a block mapping key.
+	yaml_PARSE_BLOCK_MAPPING_VALUE_STATE               // Expect a block mapping value.
+	yaml_PARSE_FLOW_SEQUENCE_FIRST_ENTRY_STATE         // Expect the first entry of a flow sequence.
+	yaml_PARSE_FLOW_SEQUENCE_ENTRY_STATE               // Expect an entry of a flow sequence.
+	yaml_PARSE_FLOW_SEQUENCE_ENTRY_MAPPING_KEY_STATE   // Expect a key of an ordered mapping.
+	yaml_PARSE_FLOW_SEQUENCE_ENTRY_MAPPING_VALUE_STATE // Expect a value of an ordered mapping.
+	yaml_PARSE_FLOW_SEQUENCE_ENTRY_MAPPING_END_STATE   // Expect the and of an ordered mapping entry.
+	yaml_PARSE_FLOW_MAPPING_FIRST_KEY_STATE            // Expect the first key of a flow mapping.
+	yaml_PARSE_FLOW_MAPPING_KEY_STATE                  // Expect a key of a flow mapping.
+	yaml_PARSE_FLOW_MAPPING_VALUE_STATE                // Expect a value of a flow mapping.
+	yaml_PARSE_FLOW_MAPPING_EMPTY_VALUE_STATE          // Expect an empty value of a flow mapping.
+	yaml_PARSE_END_STATE                               // Expect nothing.
+)
+
+func (ps yaml_parser_state_t) String() string {
+	switch ps {
+	case yaml_PARSE_STREAM_START_STATE:
+		return "yaml_PARSE_STREAM_START_STATE"
+	case yaml_PARSE_IMPLICIT_DOCUMENT_START_STATE:
+		return "yaml_PARSE_IMPLICIT_DOCUMENT_START_STATE"
+	case yaml_PARSE_DOCUMENT_START_STATE:
+		return "yaml_PARSE_DOCUMENT_START_STATE"
+	case yaml_PARSE_DOCUMENT_CONTENT_STATE:
+		return "yaml_PARSE_DOCUMENT_CONTENT_STATE"
+	case yaml_PARSE_DOCUMENT_END_STATE:
+		return "yaml_PARSE_DOCUMENT_END_STATE"
+	case yaml_PARSE_BLOCK_NODE_STATE:
+		return "yaml_PARSE_BLOCK_NODE_STATE"
+	case yaml_PARSE_BLOCK_NODE_OR_INDENTLESS_SEQUENCE_STATE:
+		return "yaml_PARSE_BLOCK_NODE_OR_INDENTLESS_SEQUENCE_STATE"
+	case yaml_PARSE_FLOW_NODE_STATE:
+		return "yaml_PARSE_FLOW_NODE_STATE"
+	case yaml_PARSE_BLOCK_SEQUENCE_FIRST_ENTRY_STATE:
+		return "yaml_PARSE_BLOCK_SEQUENCE_FIRST_ENTRY_STATE"
+	case yaml_PARSE_BLOCK_SEQUENCE_ENTRY_STATE:
+		return "yaml_PARSE_BLOCK_SEQUENCE_ENTRY_STATE"
+	case yaml_PARSE_INDENTLESS_SEQUENCE_ENTRY_STATE:
+		return "yaml_PARSE_INDENTLESS_SEQUENCE_ENTRY_STATE"
+	case yaml_PARSE_BLOCK_MAPPING_FIRST_KEY_STATE:
+		return "yaml_PARSE_BLOCK_MAPPING_FIRST_KEY_STATE"
+	case yaml_PARSE_BLOCK_MAPPING_KEY_STATE:
+		return "yaml_PARSE_BLOCK_MAPPING_KEY_STATE"
+	case yaml_PARSE_BLOCK_MAPPING_VALUE_STATE:
+		return "yaml_PARSE_BLOCK_MAPPING_VALUE_STATE"
+	case yaml_PARSE_FLOW_SEQUENCE_FIRST_ENTRY_STATE:
+		return "yaml_PARSE_FLOW_SEQUENCE_FIRST_ENTRY_STATE"
+	case yaml_PARSE_FLOW_SEQUENCE_ENTRY_STATE:
+		return "yaml_PARSE_FLOW_SEQUENCE_ENTRY_STATE"
+	case yaml_PARSE_FLOW_SEQUENCE_ENTRY_MAPPING_KEY_STATE:
+		return "yaml_PARSE_FLOW_SEQUENCE_ENTRY_MAPPING_KEY_STATE"
+	case yaml_PARSE_FLOW_SEQUENCE_ENTRY_MAPPING_VALUE_STATE:
+		return "yaml_PARSE_FLOW_SEQUENCE_ENTRY_MAPPING_VALUE_STATE"
+	case yaml_PARSE_FLOW_SEQUENCE_ENTRY_MAPPING_END_STATE:
+		return "yaml_PARSE_FLOW_SEQUENCE_ENTRY_MAPPING_END_STATE"
+	case yaml_PARSE_FLOW_MAPPING_FIRST_KEY_STATE:
+		return "yaml_PARSE_FLOW_MAPPING_FIRST_KEY_STATE"
+	case yaml_PARSE_FLOW_MAPPING_KEY_STATE:
+		return "yaml_PARSE_FLOW_MAPPING_KEY_STATE"
+	case yaml_PARSE_FLOW_MAPPING_VALUE_STATE:
+		return "yaml_PARSE_FLOW_MAPPING_VALUE_STATE"
+	case yaml_PARSE_FLOW_MAPPING_EMPTY_VALUE_STATE:
+		return "yaml_PARSE_FLOW_MAPPING_EMPTY_VALUE_STATE"
+	case yaml_PARSE_END_STATE:
+		return "yaml_PARSE_END_STATE"
+	}
+	return "<unknown parser state>"
+}
+
+// This structure holds aliases data.
+type yaml_alias_data_t struct {
+	anchor []byte      // The anchor.
+	index  int         // The node id.
+	mark   yaml_mark_t // The anchor mark.
+}
+
+// The parser structure.
+//
+// All members are internal. Manage the structure using the
+// yaml_parser_ family of functions.
+type yaml_parser_t struct {
+
+	// Error handling
+
+	error yaml_error_type_t // Error type.
+
+	problem string // Error description.
+
+	// The byte about which the problem occurred.
+	problem_offset int
+	problem_value  int
+	problem_mark   yaml_mark_t
+
+	// The error context.
+	context      string
+	context_mark yaml_mark_t
+
+	// Reader stuff
+
+	read_handler yaml_read_handler_t // Read handler.
+
+	input_reader io.Reader // File input data.
+	input        []byte    // String input data.
+	input_pos    int
+
+	eof bool // EOF flag
+
+	buffer     []byte // The working buffer.
+	buffer_pos int    // The current position of the buffer.
+
+	unread int // The number of unread characters in the buffer.
+
+	newlines int // The number of line breaks since last non-break/non-blank character
+
+	raw_buffer     []byte // The raw buffer.
+	raw_buffer_pos int    // The current position of the buffer.
+
+	encoding yaml_encoding_t // The input encoding.
+
+	offset int         // The offset of the current position (in bytes).
+	mark   yaml_mark_t // The mark of the current position.
+
+	// Comments
+
+	head_comment []byte // The current head comments
+	line_comment []byte // The current line comments
+	foot_comment []byte // The current foot comments
+	tail_comment []byte // Foot comment that happens at the end of a block.
+	stem_comment []byte // Comment in item preceding a nested structure (list inside list item, etc)
+
+	comments      []yaml_comment_t // The folded comments for all parsed tokens
+	comments_head int
+
+	// Scanner stuff
+
+	stream_start_produced bool // Have we started to scan the input stream?
+	stream_end_produced   bool // Have we reached the end of the input stream?
+
+	flow_level int // The number of unclosed '[' and '{' indicators.
+
+	tokens          []yaml_token_t // The tokens queue.
+	tokens_head     int            // The head of the tokens queue.
+	tokens_parsed   int            // The number of tokens fetched from the queue.
+	token_available bool           // Does the tokens queue contain a token ready for dequeueing.
+
+	indent  int   // The current indentation level.
+	indents []int // The indentation levels stack.
+
+	simple_key_allowed bool                // May a simple key occur at the current position?
+	simple_keys        []yaml_simple_key_t // The stack of simple keys.
+	simple_keys_by_tok map[int]int         // possible simple_key indexes indexed by token_number
+
+	// Parser stuff
+
+	state          yaml_parser_state_t    // The current parser state.
+	states         []yaml_parser_state_t  // The parser states stack.
+	marks          []yaml_mark_t          // The stack of marks.
+	tag_directives []yaml_tag_directive_t // The list of TAG directives.
+
+	// Dumper stuff
+
+	aliases []yaml_alias_data_t // The alias data.
+
+	document *yaml_document_t // The currently parsed document.
+}
+
+type yaml_comment_t struct {
+
+	scan_mark  yaml_mark_t // Position where scanning for comments started
+	token_mark yaml_mark_t // Position after which tokens will be associated with this comment
+	start_mark yaml_mark_t // Position of '#' comment mark
+	end_mark   yaml_mark_t // Position where comment terminated
+
+	head []byte
+	line []byte
+	foot []byte
+}
+
+// Emitter Definitions
+
+// The prototype of a write handler.
+//
+// The write handler is called when the emitter needs to flush the accumulated
+// characters to the output.  The handler should write @a size bytes of the
+// @a buffer to the output.
+//
+// @param[in,out]   data        A pointer to an application data specified by
+//                              yaml_emitter_set_output().
+// @param[in]       buffer      The buffer with bytes to be written.
+// @param[in]       size        The size of the buffer.
+//
+// @returns On success, the handler should return @c 1.  If the handler failed,
+// the returned value should be @c 0.
+//
+type yaml_write_handler_t func(emitter *yaml_emitter_t, buffer []byte) error
+
+type yaml_emitter_state_t int
+
+// The emitter states.
+const (
+	// Expect STREAM-START.
+	yaml_EMIT_STREAM_START_STATE yaml_emitter_state_t = iota
+
+	yaml_EMIT_FIRST_DOCUMENT_START_STATE       // Expect the first DOCUMENT-START or STREAM-END.
+	yaml_EMIT_DOCUMENT_START_STATE             // Expect DOCUMENT-START or STREAM-END.
+	yaml_EMIT_DOCUMENT_CONTENT_STATE           // Expect the content of a document.
+	yaml_EMIT_DOCUMENT_END_STATE               // Expect DOCUMENT-END.
+	yaml_EMIT_FLOW_SEQUENCE_FIRST_ITEM_STATE   // Expect the first item of a flow sequence.
+	yaml_EMIT_FLOW_SEQUENCE_TRAIL_ITEM_STATE   // Expect the next item of a flow sequence, with the comma already written out
+	yaml_EMIT_FLOW_SEQUENCE_ITEM_STATE         // Expect an item of a flow sequence.
+	yaml_EMIT_FLOW_MAPPING_FIRST_KEY_STATE     // Expect the first key of a flow mapping.
+	yaml_EMIT_FLOW_MAPPING_TRAIL_KEY_STATE     // Expect the next key of a flow mapping, with the comma already written out
+	yaml_EMIT_FLOW_MAPPING_KEY_STATE           // Expect a key of a flow mapping.
+	yaml_EMIT_FLOW_MAPPING_SIMPLE_VALUE_STATE  // Expect a value for a simple key of a flow mapping.
+	yaml_EMIT_FLOW_MAPPING_VALUE_STATE         // Expect a value of a flow mapping.
+	yaml_EMIT_BLOCK_SEQUENCE_FIRST_ITEM_STATE  // Expect the first item of a block sequence.
+	yaml_EMIT_BLOCK_SEQUENCE_ITEM_STATE        // Expect an item of a block sequence.
+	yaml_EMIT_BLOCK_MAPPING_FIRST_KEY_STATE    // Expect the first key of a block mapping.
+	yaml_EMIT_BLOCK_MAPPING_KEY_STATE          // Expect the key of a block mapping.
+	yaml_EMIT_BLOCK_MAPPING_SIMPLE_VALUE_STATE // Expect a value for a simple key of a block mapping.
+	yaml_EMIT_BLOCK_MAPPING_VALUE_STATE        // Expect a value of a block mapping.
+	yaml_EMIT_END_STATE                        // Expect nothing.
+)
+
+// The emitter structure.
+//
+// All members are internal.  Manage the structure using the @c yaml_emitter_
+// family of functions.
+type yaml_emitter_t struct {
+
+	// Error handling
+
+	error   yaml_error_type_t // Error type.
+	problem string            // Error description.
+
+	// Writer stuff
+
+	write_handler yaml_write_handler_t // Write handler.
+
+	output_buffer *[]byte   // String output data.
+	output_writer io.Writer // File output data.
+
+	buffer     []byte // The working buffer.
+	buffer_pos int    // The current position of the buffer.
+
+	raw_buffer     []byte // The raw buffer.
+	raw_buffer_pos int    // The current position of the buffer.
+
+	encoding yaml_encoding_t // The stream encoding.
+
+	// Emitter stuff
+
+	canonical   bool         // If the output is in the canonical style?
+	best_indent int          // The number of indentation spaces.
+	best_width  int          // The preferred width of the output lines.
+	unicode     bool         // Allow unescaped non-ASCII characters?
+	line_break  yaml_break_t // The preferred line break.
+
+	state  yaml_emitter_state_t   // The current emitter state.
+	states []yaml_emitter_state_t // The stack of states.
+
+	events      []yaml_event_t // The event queue.
+	events_head int            // The head of the event queue.
+
+	indents []int // The stack of indentation levels.
+
+	tag_directives []yaml_tag_directive_t // The list of tag directives.
+
+	indent int // The current indentation level.
+
+	flow_level int // The current flow level.
+
+	root_context       bool // Is it the document root context?
+	sequence_context   bool // Is it a sequence context?
+	mapping_context    bool // Is it a mapping context?
+	simple_key_context bool // Is it a simple mapping key context?
+
+	line       int  // The current line.
+	column     int  // The current column.
+	whitespace bool // If the last character was a whitespace?
+	indention  bool // If the last character was an indentation character (' ', '-', '?', ':')?
+	open_ended bool // If an explicit document end is required?
+
+	space_above bool // Is there's an empty line above?
+	foot_indent int  // The indent used to write the foot comment above, or -1 if none.
+
+	// Anchor analysis.
+	anchor_data struct {
+		anchor []byte // The anchor value.
+		alias  bool   // Is it an alias?
+	}
+
+	// Tag analysis.
+	tag_data struct {
+		handle []byte // The tag handle.
+		suffix []byte // The tag suffix.
+	}
+
+	// Scalar analysis.
+	scalar_data struct {
+		value                 []byte              // The scalar value.
+		multiline             bool                // Does the scalar contain line breaks?
+		flow_plain_allowed    bool                // Can the scalar be expessed in the flow plain style?
+		block_plain_allowed   bool                // Can the scalar be expressed in the block plain style?
+		single_quoted_allowed bool                // Can the scalar be expressed in the single quoted style?
+		block_allowed         bool                // Can the scalar be expressed in the literal or folded styles?
+		style                 yaml_scalar_style_t // The output style.
+	}
+
+	// Comments
+	head_comment []byte
+	line_comment []byte
+	foot_comment []byte
+	tail_comment []byte
+
+	key_line_comment []byte
+
+	// Dumper stuff
+
+	opened bool // If the stream was already opened?
+	closed bool // If the stream was already closed?
+
+	// The information associated with the document nodes.
+	anchors *struct {
+		references int  // The number of references.
+		anchor     int  // The anchor id.
+		serialized bool // If the node has been emitted?
+	}
+
+	last_anchor_id int // The last assigned anchor id.
+
+	document *yaml_document_t // The currently emitted document.
+}
diff --git a/vendor/gopkg.in/yaml.v3/yamlprivateh.go b/vendor/gopkg.in/yaml.v3/yamlprivateh.go
new file mode 100644
index 000000000000..e88f9c54aecb
--- /dev/null
+++ b/vendor/gopkg.in/yaml.v3/yamlprivateh.go
@@ -0,0 +1,198 @@
+// 
+// Copyright (c) 2011-2019 Canonical Ltd
+// Copyright (c) 2006-2010 Kirill Simonov
+// 
+// Permission is hereby granted, free of charge, to any person obtaining a copy of
+// this software and associated documentation files (the "Software"), to deal in
+// the Software without restriction, including without limitation the rights to
+// use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+// of the Software, and to permit persons to whom the Software is furnished to do
+// so, subject to the following conditions:
+// 
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+// 
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+package yaml
+
+const (
+	// The size of the input raw buffer.
+	input_raw_buffer_size = 512
+
+	// The size of the input buffer.
+	// It should be possible to decode the whole raw buffer.
+	input_buffer_size = input_raw_buffer_size * 3
+
+	// The size of the output buffer.
+	output_buffer_size = 128
+
+	// The size of the output raw buffer.
+	// It should be possible to encode the whole output buffer.
+	output_raw_buffer_size = (output_buffer_size*2 + 2)
+
+	// The size of other stacks and queues.
+	initial_stack_size  = 16
+	initial_queue_size  = 16
+	initial_string_size = 16
+)
+
+// Check if the character at the specified position is an alphabetical
+// character, a digit, '_', or '-'.
+func is_alpha(b []byte, i int) bool {
+	return b[i] >= '0' && b[i] <= '9' || b[i] >= 'A' && b[i] <= 'Z' || b[i] >= 'a' && b[i] <= 'z' || b[i] == '_' || b[i] == '-'
+}
+
+// Check if the character at the specified position is a digit.
+func is_digit(b []byte, i int) bool {
+	return b[i] >= '0' && b[i] <= '9'
+}
+
+// Get the value of a digit.
+func as_digit(b []byte, i int) int {
+	return int(b[i]) - '0'
+}
+
+// Check if the character at the specified position is a hex-digit.
+func is_hex(b []byte, i int) bool {
+	return b[i] >= '0' && b[i] <= '9' || b[i] >= 'A' && b[i] <= 'F' || b[i] >= 'a' && b[i] <= 'f'
+}
+
+// Get the value of a hex-digit.
+func as_hex(b []byte, i int) int {
+	bi := b[i]
+	if bi >= 'A' && bi <= 'F' {
+		return int(bi) - 'A' + 10
+	}
+	if bi >= 'a' && bi <= 'f' {
+		return int(bi) - 'a' + 10
+	}
+	return int(bi) - '0'
+}
+
+// Check if the character is ASCII.
+func is_ascii(b []byte, i int) bool {
+	return b[i] <= 0x7F
+}
+
+// Check if the character at the start of the buffer can be printed unescaped.
+func is_printable(b []byte, i int) bool {
+	return ((b[i] == 0x0A) || // . == #x0A
+		(b[i] >= 0x20 && b[i] <= 0x7E) || // #x20 <= . <= #x7E
+		(b[i] == 0xC2 && b[i+1] >= 0xA0) || // #0xA0 <= . <= #xD7FF
+		(b[i] > 0xC2 && b[i] < 0xED) ||
+		(b[i] == 0xED && b[i+1] < 0xA0) ||
+		(b[i] == 0xEE) ||
+		(b[i] == 0xEF && // #xE000 <= . <= #xFFFD
+			!(b[i+1] == 0xBB && b[i+2] == 0xBF) && // && . != #xFEFF
+			!(b[i+1] == 0xBF && (b[i+2] == 0xBE || b[i+2] == 0xBF))))
+}
+
+// Check if the character at the specified position is NUL.
+func is_z(b []byte, i int) bool {
+	return b[i] == 0x00
+}
+
+// Check if the beginning of the buffer is a BOM.
+func is_bom(b []byte, i int) bool {
+	return b[0] == 0xEF && b[1] == 0xBB && b[2] == 0xBF
+}
+
+// Check if the character at the specified position is space.
+func is_space(b []byte, i int) bool {
+	return b[i] == ' '
+}
+
+// Check if the character at the specified position is tab.
+func is_tab(b []byte, i int) bool {
+	return b[i] == '\t'
+}
+
+// Check if the character at the specified position is blank (space or tab).
+func is_blank(b []byte, i int) bool {
+	//return is_space(b, i) || is_tab(b, i)
+	return b[i] == ' ' || b[i] == '\t'
+}
+
+// Check if the character at the specified position is a line break.
+func is_break(b []byte, i int) bool {
+	return (b[i] == '\r' || // CR (#xD)
+		b[i] == '\n' || // LF (#xA)
+		b[i] == 0xC2 && b[i+1] == 0x85 || // NEL (#x85)
+		b[i] == 0xE2 && b[i+1] == 0x80 && b[i+2] == 0xA8 || // LS (#x2028)
+		b[i] == 0xE2 && b[i+1] == 0x80 && b[i+2] == 0xA9) // PS (#x2029)
+}
+
+func is_crlf(b []byte, i int) bool {
+	return b[i] == '\r' && b[i+1] == '\n'
+}
+
+// Check if the character is a line break or NUL.
+func is_breakz(b []byte, i int) bool {
+	//return is_break(b, i) || is_z(b, i)
+	return (
+		// is_break:
+		b[i] == '\r' || // CR (#xD)
+		b[i] == '\n' || // LF (#xA)
+		b[i] == 0xC2 && b[i+1] == 0x85 || // NEL (#x85)
+		b[i] == 0xE2 && b[i+1] == 0x80 && b[i+2] == 0xA8 || // LS (#x2028)
+		b[i] == 0xE2 && b[i+1] == 0x80 && b[i+2] == 0xA9 || // PS (#x2029)
+		// is_z:
+		b[i] == 0)
+}
+
+// Check if the character is a line break, space, or NUL.
+func is_spacez(b []byte, i int) bool {
+	//return is_space(b, i) || is_breakz(b, i)
+	return (
+		// is_space:
+		b[i] == ' ' ||
+		// is_breakz:
+		b[i] == '\r' || // CR (#xD)
+		b[i] == '\n' || // LF (#xA)
+		b[i] == 0xC2 && b[i+1] == 0x85 || // NEL (#x85)
+		b[i] == 0xE2 && b[i+1] == 0x80 && b[i+2] == 0xA8 || // LS (#x2028)
+		b[i] == 0xE2 && b[i+1] == 0x80 && b[i+2] == 0xA9 || // PS (#x2029)
+		b[i] == 0)
+}
+
+// Check if the character is a line break, space, tab, or NUL.
+func is_blankz(b []byte, i int) bool {
+	//return is_blank(b, i) || is_breakz(b, i)
+	return (
+		// is_blank:
+		b[i] == ' ' || b[i] == '\t' ||
+		// is_breakz:
+		b[i] == '\r' || // CR (#xD)
+		b[i] == '\n' || // LF (#xA)
+		b[i] == 0xC2 && b[i+1] == 0x85 || // NEL (#x85)
+		b[i] == 0xE2 && b[i+1] == 0x80 && b[i+2] == 0xA8 || // LS (#x2028)
+		b[i] == 0xE2 && b[i+1] == 0x80 && b[i+2] == 0xA9 || // PS (#x2029)
+		b[i] == 0)
+}
+
+// Determine the width of the character.
+func width(b byte) int {
+	// Don't replace these by a switch without first
+	// confirming that it is being inlined.
+	if b&0x80 == 0x00 {
+		return 1
+	}
+	if b&0xE0 == 0xC0 {
+		return 2
+	}
+	if b&0xF0 == 0xE0 {
+		return 3
+	}
+	if b&0xF8 == 0xF0 {
+		return 4
+	}
+	return 0
+
+}
diff --git a/vendor/modules.txt b/vendor/modules.txt
index a9627e8c2978..78ee69b33ab7 100644
--- a/vendor/modules.txt
+++ b/vendor/modules.txt
@@ -33,12 +33,20 @@ github.com/containerd/containerd/platforms
 # github.com/containerd/log v0.1.0
 ## explicit; go 1.20
 github.com/containerd/log
+# github.com/cpuguy83/go-md2man/v2 v2.0.3
+## explicit; go 1.11
+github.com/cpuguy83/go-md2man/v2
+github.com/cpuguy83/go-md2man/v2/md2man
 # github.com/creack/pty v1.1.21
 ## explicit; go 1.13
 github.com/creack/pty
 # github.com/distribution/reference v0.5.0
 ## explicit; go 1.20
 github.com/distribution/reference
+# github.com/docker/cli-docs-tool v0.6.0
+## explicit; go 1.18
+github.com/docker/cli-docs-tool
+github.com/docker/cli-docs-tool/annotation
 # github.com/docker/distribution v2.8.3+incompatible
 ## explicit
 github.com/docker/distribution
@@ -252,12 +260,16 @@ github.com/prometheus/procfs/internal/util
 # github.com/rivo/uniseg v0.2.0
 ## explicit; go 1.12
 github.com/rivo/uniseg
+# github.com/russross/blackfriday/v2 v2.1.0
+## explicit
+github.com/russross/blackfriday/v2
 # github.com/sirupsen/logrus v1.9.3
 ## explicit; go 1.13
 github.com/sirupsen/logrus
 # github.com/spf13/cobra v1.8.0
 ## explicit; go 1.15
 github.com/spf13/cobra
+github.com/spf13/cobra/doc
 # github.com/spf13/pflag v1.0.5
 ## explicit; go 1.12
 github.com/spf13/pflag
@@ -521,6 +533,9 @@ google.golang.org/protobuf/types/known/wrapperspb
 # gopkg.in/yaml.v2 v2.4.0
 ## explicit; go 1.15
 gopkg.in/yaml.v2
+# gopkg.in/yaml.v3 v3.0.1
+## explicit
+gopkg.in/yaml.v3
 # gotest.tools/v3 v3.5.1
 ## explicit; go 1.17
 gotest.tools/v3/assert
-- 
2.44.0

Places

File cli-0001-docs-include-required-tools-in-source-tree.patch of Package docker (Revision 21792492e8ab20f60c746145f30a6d4c)

Places