assertFalse(future.isCancelled());

    ExecutorService executor = newSingleThreadExecutor();

    try {
      Future<Boolean> getResult = executor.submit(() -> future.get());

      // Release the future value.
      latch.countDown();

      assertTrue(getResult.get(10, SECONDS));
    } finally {
      executor.shutdownNow();
    }

    assertTrue(future.isDone());

    // There is no thread interruption in GWT, so there's nothing to do.
  }

  static <V extends @Nullable Object> V getDoneFromTimeoutOverload(Future<V> future)
      throws ExecutionException {
    checkState(future.isDone(), "Future was expected to be done: %s", future);
    try {
      return future.get(0, SECONDS);
    } catch (InterruptedException e) {
      throw new AssertionError();
    } catch (TimeoutException e) {

 * <p>Useful for testing the behavior of Future utilities against odd futures.
 *
 * @author Anthony Zana
 */
@GwtCompatible
@NullUnmarked
final class UncheckedThrowingFuture<V> extends AbstractFuture<V> {

  public static <V> ListenableFuture<V> throwingError(Error error) {
    UncheckedThrowingFuture<V> future = new UncheckedThrowingFuture<V>();
    future.complete(checkNotNull(error));
    return future;
  }

  }

  public void testCancel_notDoneNoInterrupt() throws Exception {
    Future<?> future = newFutureInstance();
    assertTrue(future.cancel(false));
    assertTrue(future.isCancelled());
    assertTrue(future.isDone());
    assertNull(tryInternalFastPathGetFailure(future));
    CancellationException e = assertThrows(CancellationException.class, () -> future.get());
    assertNotNull(e.getCause());
  }

  }

  public void testCancel_notDoneNoInterrupt() throws Exception {
    Future<?> future = newFutureInstance();
    assertTrue(future.cancel(false));
    assertTrue(future.isCancelled());
    assertTrue(future.isDone());
    assertNull(tryInternalFastPathGetFailure(future));
    CancellationException e = assertThrows(CancellationException.class, () -> future.get());
    assertNotNull(e.getCause());
  }

    assertTrue(future.isDone());
    assertTrue(future.isCancelled());

    assertThrows(CancellationException.class, () -> future.get());
  }

  public void testFailedFuture(@Nullable String message) throws InterruptedException {
    assertTrue(future.isDone());
    assertFalse(future.isCancelled());

    assertTrue(latch.await(5, SECONDS));
    assertTrue(future.isDone());
    assertFalse(future.isCancelled());

    SettableFuture<@Nullable Void> future = SettableFuture.create();
    Object unused =
        new Object() {
          @SuppressWarnings({"removal", "Finalize"}) // b/260137033
          @Override
          protected void finalize() {
            future.set(null);
          }
        };
    unused = null; // Hint to the JIT that unused is unreachable
    GcFinalization.awaitDone(future);
    assertTrue(future.isDone());

            taskDone = true;
            return taskDone;
          }
        };
    List<Future<Boolean>> futureList = executor.invokeAll(ImmutableList.of(task), 10, MILLISECONDS);
    Future<Boolean> future = futureList.get(0);
    assertFalse(taskDone);
    assertTrue(future.isDone());
    assertThrows(CancellationException.class, () -> future.get());
  }

            taskDone = true;
            return taskDone;
          }
        };
    List<Future<Boolean>> futureList = executor.invokeAll(ImmutableList.of(task), 10, MILLISECONDS);
    Future<Boolean> future = futureList.get(0);
    assertFalse(taskDone);
    assertTrue(future.isDone());
    assertThrows(CancellationException.class, () -> future.get());
  }

    }

    @Override
    public <T> Future<T> submit(Callable<T> task) {
      throw new UnsupportedOperationException();
    }

    @Override
    public Future<?> submit(Runnable task) {
      throw new UnsupportedOperationException();
    }

    @Override
    public <T> Future<T> submit(Runnable task, T result) {
      throw new UnsupportedOperationException();
    }