You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: test_parser_context.rb
    path of file: ./repos/stackneveroverflow/vendor/bundle/ruby/2.3.0/gems/nokogiri-1.8.0/test/html/sax
    
    the code of the file until where you have to start completion: # -*- coding: utf-8 -*-

require "helper"

module Nokogiri
  module HTML
    module SAX
      class TestParserContext < Nokogiri::SAX::TestCase
        def test_from_io
          ctx = ParserContext.new StringIO.new('fo'), 'UTF-8'
          assert ctx
        end

        def test_from_string
          ctx = Pa
    
        def test_parse_with_sax_parser
          # assert_nothing_raised do
            xml = "<root />"
            ctx = ParserContext.new xml
            parser = Parser.new Doc.new
            ctx.parse_with parser
          # end
        end

        def test_from_file
          # assert_nothing_raised do
            ctx = ParserContext.file HTML_FILE, 'UTF-8'
            parser = Parser.new Doc.new
            ctx.parse_with parser
          # end
        end
      end
    end