Add graph container null context protection test. #137

	# This workflow validates the document for markup and examples.
	name: CI

	on:
	push:
	branches: [ '**' ]
	pull_request:
	branches: [ main ]

	jobs:
	tests:
	name: Build and Validate
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@v3
	- name: Set up Ruby
	uses: ruby/setup-ruby@v1
	with:
	ruby-version: 3.2
	- name: Install dependencies
	run: bundle install

	- name: "Verify common files are consistent"
	run: \|
	git remote add -f b https://github.com/w3c/json-ld-wg.git
	git remote update
	git diff --exit-code remotes/b/main -- common

	- name: Verify examples are consistent
	run: bundle exec rake test

	- name: Checks HTML5
	run: bundle exec rake check_html

	# See https://github.com/w3c/spec-prod/blob/main/docs/examples.md
	#- name: ReSpec Checker
	# uses: w3c/spec-prod@v1
	# with:
	# VALIDATE_LINKS: true
	# VALIDATE_MARKUP: true

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