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: file_changes_test.rb
    path of file: ./repos/retest/features/ruby-app/retest/retest_test
    
    the code of the file until where you have to start completion: class FileChangesTest < Minitest::Test
  def setup
    @command = 'retest --ruby'
  end

  def teardown
    end_retest @output, @pid
  end

  def test_start_retest
    @output, @pid = launch_retest @command

    assert_match <<~EXPECTED, @output.read
      Launching Retest...
      Ready to refactor! You can make file changes now
    EXPEC
    
  def test_creating_a_new_file
    @output, @pid = launch_retest @command

    create_file 'foo.rb'
    assert_match <<~EXPECTED, @output.read
      404 - Test File Not Found
      Retest could not find a matching test file to run.
    EXPECTED

    create_file 'foo_test.rb'
    assert_match "Test File Selected: foo_test.rb", @output.read

    modify_file('lib/bottles.rb')
    assert_match "Test File Selected: test/bottles_test.rb", @output.read

    modify_file('foo.rb')
    assert_match "Test File Selected: foo_test.rb", @output.read

    delete_file 'foo.rb'
    delete_file 'foo_test.rb'
  end