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_gem_commands_stale_command.rb
    path of file: ./repos/artichoke/artichoke-backend/vendor/ruby/test/rubygems
    
    the code of the file until where you have to start completion: # frozen_string_literal: true
require_relative 'helper'
require 'rubygems/commands/stale_command'

class TestGemCommandsStaleCommand < Gem::TestCase
  def setup
    super
    @stub_ui = Gem::MockGemUi.new
    @cmd = Gem::Commands::StaleCommand.new
  end

  def test_execute_sorts
    files = %w[lib/foo_bar.rb Rakefile]
    foo_bar = util_spec 'foo_bar' do |gem|
      gem.files = files
    end
    install_specs foo_bar

    bar_baz = util_spec 'bar_baz' do |gem|
      gem.files = files
    end
    install_specs bar_baz

    files.each do |file|
      filename = File.join(bar_baz.full_gem_path, file)
      FileUtils.mkdir_p File.dirname f
    
  def test_execute_sorts
    files = %w[lib/foo_bar.rb Rakefile]
    foo_bar = util_spec 'foo_bar' do |gem|
      gem.files = files
    end
    install_specs foo_bar

    bar_baz = util_spec 'bar_baz' do |gem|
      gem.files = files
    end
    install_specs bar_baz

    files.each do |file|
      filename = File.join(bar_baz.full_gem_path, file)
      FileUtils.mkdir_p File.dirname filename
      FileUtils.touch(filename, :mtime => Time.now)

      filename = File.join(foo_bar.full_gem_path, file)
      FileUtils.mkdir_p File.dirname filename
      FileUtils.touch(filename, :mtime => Time.now - 86400)
    end

    use_ui @stub_ui do
      @cmd.execute
    end

    lines = @stub_ui.output.split("\n")
    assert_equal("#{foo_bar.name}-#{foo_bar.version}", lines[0].split.first)
    assert_equal("#{bar_baz.name}-#{bar_baz.version}", lines[1].split.first)
  end