def METHOD_NAME():
    """Mailbox awaits futures before passing them to readers."""
    # Timeouts are longer for this example,
    # since they involve creating subprocesses.
    exc = concurrent.futures.ProcessPoolExecutor()
    futures = [exc.submit(_task, i) for i in range(3)]
    mailbox_tester(futures,
                   expected_result=[0, 1, 2],
                   result_timeout=5 * LONG_TIMEOUT,
                   timeout=5 * LONG_TIMEOUT)