protected final void afterDone() {
    super.afterDone();

    ImmutableCollection<? extends Future<?>> localFutures = futures;
    releaseResources(OUTPUT_FUTURE_DONE); // nulls out `futures`

    if (isCancelled() & localFutures != null) {
      boolean wasInterrupted = wasInterrupted();
      for (Future<?> future : localFutures) {
        future.cancel(wasInterrupted);
      }
    }
    /*

import static com.google.common.util.concurrent.FuturesGetCheckedInputs.FAILED_FUTURE_ERROR;
import static com.google.common.util.concurrent.FuturesGetCheckedInputs.FAILED_FUTURE_OTHER_THROWABLE;
import static com.google.common.util.concurrent.FuturesGetCheckedInputs.FAILED_FUTURE_UNCHECKED_EXCEPTION;
import static com.google.common.util.concurrent.FuturesGetCheckedInputs.OTHER_THROWABLE;

  private static void assertSetAsynchronously(AbstractFuture<Integer> future) {
    assertCannotSet(future);
    assertPending(future);
  }

  private static void assertPending(AbstractFuture<Integer> future) {
    assertThat(future.isDone()).isFalse();
    assertThat(future.isCancelled()).isFalse();

    CountingRunnable listener = new CountingRunnable();
    future.addListener(listener, directExecutor());
    listener.assertNotRun();

  }

  /**
   * Returns a new {@code Future} whose result is asynchronously derived from the result of this
   * {@code Future}. If the input {@code Future} fails, the returned {@code Future} fails with the
   * same exception (and the function is not invoked).
   *
   * <p>More precisely, the returned {@code Future} takes its result from a {@code Future} produced

  }

  /**
   * Invokes {@code future.}{@link Future#get() get()} uninterruptibly.
   *
   * <p>Similar methods:
   *
   * <ul>
   *   <li>To retrieve a result from a {@code Future} that is already done, use {@link
   *       Futures#getDone Futures.getDone}.
   *   <li>To treat {@link InterruptedException} uniformly with other exceptions, use {@link
   *       Futures#getChecked(Future, Class) Futures.getChecked}.

      List<Future<String>> futures = testExecutor.invokeAll(tasks);
      mock.assertLastMethodCalled("invokeAll");
      checkResults(futures);
    }
    {
      MockExecutor mock = new MockExecutor();
      TimeUnit unit = TimeUnit.SECONDS;
      long timeout = 5;
      TestExecutor testExecutor = new TestExecutor(mock);
      List<Future<String>> futures = testExecutor.invokeAll(tasks, timeout, unit);

  @CanIgnoreReturnValue
  protected boolean setFuture(ListenableFuture<? extends V> future) {
    checkNotNull(future);

    // If this future is already cancelled, cancel the delegate.
    // TODO(cpovirk): Should we do this at the end of the method, as in the server version?
    // TODO(cpovirk): Use maybePropagateCancellationTo?
    if (isCancelled()) {
      future.cancel(mayInterruptIfRunning);
    }

    InterruptibleFuture future = new InterruptibleFuture();
    assertTrue(future.cancel(false));
    assertTrue(future.isCancelled());
    assertTrue(future.isDone());
    assertFalse(future.wasInterrupted());
    assertFalse(future.interruptTaskWasCalled);
    CancellationException e = assertThrows(CancellationException.class, () -> future.get());
    assertThat(e).hasCauseThat().isNull();
  }

  private static void assertSetAsynchronously(AbstractFuture<Integer> future) {
    assertCannotSet(future);
    assertPending(future);
  }

  private static void assertPending(AbstractFuture<Integer> future) {
    assertThat(future.isDone()).isFalse();
    assertThat(future.isCancelled()).isFalse();

    CountingRunnable listener = new CountingRunnable();
    future.addListener(listener, directExecutor());
    listener.assertNotRun();

      Future<?> possiblyIgnoredError = threadPool.submit(new Producer(q, 20));
      @SuppressWarnings("unused") // https://errorprone.info/bugpattern/FutureReturnValueIgnored
      Future<?> possiblyIgnoredError1 = threadPool.submit(new Producer(q, 20));
      @SuppressWarnings("unused") // https://errorprone.info/bugpattern/FutureReturnValueIgnored