class Cucumber::Formatter::MessageBuilder

def on_test_case_finished(event)
  message = Cucumber::Messages::Envelope.new(
    test_case_finished: Cucumber::Messages::TestCaseFinished.new(
      test_case_started_id: test_case_started_id(event.test_case),
      timestamp: time_to_timestamp(Time.now)
    )
  )
  output_envelope(message)
end