}

  public void testAddListenerAfterCallback() throws Throwable {
    inputFuture.set(VALID_INPUT_DATA);

    listener.assertSuccess(getSuccessfulResult());
  }

  public void testFutureBeforeCallback() throws Throwable {
    inputFuture.set(VALID_INPUT_DATA);

    listener.assertSuccess(getSuccessfulResult());
  }

  public void testInputFutureToString() throws Throwable {

   * returns the expected data.
   *
   * @throws Throwable if the listener isn't called or if it resulted in a throwable or if the
   *     result doesn't match the expected value.
   */
  public void assertSuccess(Object expectedData) throws Throwable {
    // Verify that the listener executed in a reasonable amount of time.
    Assert.assertTrue(countDownLatch.await(1L, SECONDS));

    try {