Fix JSON Serializer generating json with attributes with a null value #192

	# This workflow uses actions that are not certified by GitHub.
	# They are provided by a third-party and are governed by
	# separate terms of service, privacy policy, and support
	# documentation.
	# This workflow will download a prebuilt Ruby version, install dependencies and run tests with Rake
	# For more information see: https://github.com/marketplace/actions/setup-ruby-jruby-and-truffleruby

	name: build

	on:
	push:
	branches: [master]
	pull_request:
	types: [opened, synchronize]

	jobs:
	test:
	runs-on: ubuntu-20.04
	strategy:
	fail-fast: false
	matrix:
	ruby:
	- '3.4.0-preview2'
	- '3.3'
	- '3.2'
	- '3.1'
	- '3.0'
	- '2.7'
	- '2.6'
	- '2.5'
	- truffleruby
	steps:
	- uses: actions/checkout@v4
	- uses: ruby/setup-ruby@v1
	with:
	ruby-version: ${{ matrix.ruby }}
	bundler-cache: true
	- run: bundle exec rspec
	env:
	RUBYOPT: ${{ startsWith(matrix.ruby, '3.4') && '--enable=frozen-string-literal' \|\| '' }}

	lint:
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@v4
	- uses: ruby/setup-ruby@v1
	with:
	ruby-version: '3.3'
	bundler-cache: true
	- run: bundle exec rubocop -f github

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