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_cgi_util.rb
    path of file: ./repos/ruby-packer/ruby/test/cgi
    
    the code of the file until where you have to start completion: # frozen_string_literal: true
require 'test/unit'
require 'cgi'
require 'string
    
  def test_cgi_unescape_accept_charset
    return unless defined?(::Encoding)

    assert_raise(TypeError) {CGI.unescape('', nil)}
    assert_separately(%w[-rcgi/util], "#{<<-"begin;"}\n#{<<-"end;"}")
    begin;
      assert_equal("", CGI.unescape(''))
    end;
  end