Assert.assertTrue(countDownLatch.await(1L, SECONDS));

    try {
      future.get();
      Assert.fail("This call was supposed to throw an ExecutionException");
    } catch (ExecutionException expected) {
      Assert.assertSame(expectedCause, expected.getCause());
    }
  }

  public void assertTimeout() throws Exception {

       * a {@link CancellationException} if the task was cancelled, or a {@link ExecutionException}
       * if the task completed with an error.
       */
      V get() throws CancellationException, ExecutionException, InterruptedException {

        // Acquire the shared lock allowing interruption.
        acquireSharedInterruptibly(-1);
        return getValue();

    try {
      valueAndCloser.get();
      fail();
    } catch (ExecutionException expected) {
      assertThat(expected).hasCauseThat().isSameInstanceAs(exception);
    }
    valueAndCloser.closeAsync();
  }

  @Override
  void assertBecomesCanceled(ClosingFuture<?> closingFuture) throws ExecutionException {
    assertThatFutureBecomesCancelled(closingFuture.statusFuture());
  }

  @Override

       * a {@link CancellationException} if the task was cancelled, or a {@link ExecutionException}
       * if the task completed with an error.
       */
      V get() throws CancellationException, ExecutionException, InterruptedException {

        // Acquire the shared lock allowing interruption.
        acquireSharedInterruptibly(-1);
        return getValue();

    private static void run(String... cmd) throws IOException, InterruptedException, ExecutionException {
        ExecResult r = exec(cmd);
        if (r.exitCode() != 0) {
            throw new AssertionError(String.join(" ", cmd) + " failed: " + r);
        }
    }

    private static String stdout(String... cmd) throws IOException, InterruptedException, ExecutionException {
        ExecResult r = exec(cmd);
        if (r.exitCode() != 0) {

  }

  /**
   * Marks the given step final, waits for it to be finished, and returns the value.
   *
   * @throws ExecutionException if the step failed
   * @throws CancellationException if the step was cancelled
   */
  abstract <T> T getFinalValue(ClosingFuture<T> closingFuture) throws ExecutionException;

  /** Marks the given step final, cancels it, and waits for the cancellation to happen. */

    try {
      getDone(future);
      fail();
    } catch (ExecutionException e) {
      assertThat(e).hasCauseThat().isSameInstanceAs(expectedException);
    }

    try {
      getDoneFromTimeoutOverload(future);
      fail();
    } catch (ExecutionException e) {
      assertThat(e).hasCauseThat().isSameInstanceAs(expectedException);
    }

            () -> {
              throw e;
            });
    task.run();
    assertTrue(task.isDone());
    assertFalse(task.isCancelled());
    ExecutionException executionException =
        assertThrows(ExecutionException.class, () -> getDone(task));
    assertThat(executionException).hasCauseThat().isEqualTo(e);
  }

  @J2ktIncompatible
  @GwtIncompatible // blocking wait
  public void testCancel_interrupted() throws Exception {

    return getUninterruptibly(closingFuture.finishToFuture());
  }

  @Override
  void assertFinallyFailsWithException(ClosingFuture<?> closingFuture) {
    assertThatFutureFailsWithException(closingFuture.finishToFuture());
  }

  @Override
  void assertBecomesCanceled(ClosingFuture<?> closingFuture) throws ExecutionException {

  }

  @Override
  @CanIgnoreReturnValue
  @ParametricNullness
  public V get() throws InterruptedException, ExecutionException {
    return delegate().get();
  }

  @Override
  @CanIgnoreReturnValue
  @ParametricNullness
  public V get(long timeout, TimeUnit unit)
      throws InterruptedException, ExecutionException, TimeoutException {
    return delegate().get(timeout, unit);
  }