inputFuture.setException(EXCEPTION);
    listener.assertException(EXCEPTION);
  }

  public void testFutureGetThrowsWrappedError() throws Exception {
    Error error = new Error();
    inputFuture.setException(error);
    // Verify that get throws an ExecutionException, caused by an Error, when
    // the callback is called.
    listener.assertException(error);
  }

   * throws an {@code ExecutableException} and that the cause of the {@code ExecutableException} is
   * {@code expectedCause}.
   */
  public void assertException(Throwable expectedCause) throws Exception {
    // Verify that the listener executed in a reasonable amount of time.
    Assert.assertTrue(countDownLatch.await(1L, SECONDS));

    try {
      future.get();

          throw EXCEPTION;
      }
      return outputFuture;
    }
  }

  public void testFutureGetThrowsFunctionException() throws Exception {
    inputFuture.set(EXCEPTION_DATA);
    listener.assertException(EXCEPTION);
  }

  public void testFutureGetThrowsCancellationIfInputCancelled() throws Exception {
    inputFuture.cancel(true); // argument is ignored

          throw EXCEPTION;
      }
      return outputFuture;
    }
  }

  public void testFutureGetThrowsFunctionException() throws Exception {
    inputFuture.set(EXCEPTION_DATA);
    listener.assertException(EXCEPTION);
  }

  public void testFutureGetThrowsCancellationIfInputCancelled() throws Exception {
    inputFuture.cancel(true); // argument is ignored