* Future} instances to be upgraded to {@code ListenableFuture} after the fact.
   */
  public static <V extends @Nullable Object> ListenableFuture<V> listenInPoolThread(
      Future<V> future) {
    if (future instanceof ListenableFuture) {
      return (ListenableFuture<V>) future;
    }
    return new ListenableFutureAdapter<>(future);
  }

  /**

  public static <V extends @Nullable Object> V getUninterruptibly(
      Future<V> future, Duration timeout) throws ExecutionException, TimeoutException {
    return getUninterruptibly(future, toNanosSaturated(timeout), NANOSECONDS);
  }

  /**
   * Invokes {@code future.}{@link Future#get(long, TimeUnit) get(timeout, unit)} uninterruptibly.
   *
   * <p>Similar methods:
   *
   * <ul>

   * completes. Cancelling the supplied future will also cancel the returned future, but cancelling
   * the returned future will have no effect on the supplied future.
   *
   * @since 15.0
   */
  public static <V extends @Nullable Object> ListenableFuture<V> nonCancellationPropagating(
      ListenableFuture<V> future) {
    if (future.isDone()) {
      return future;
    }

    SettableFuture<Integer> future = SettableFuture.create();
    assertTrue(future.set(42));
    // Later attempts to set the future should return false.
    assertFalse(future.set(23));
    assertFalse(future.setException(new Exception("bar")));
    assertFalse(future.setFuture(SettableFuture.create()));
    // Check that the future has been set properly.
    assertTrue(future.isDone());
    assertFalse(future.isCancelled());

  /**
   * Sets the result of this {@code Future} to match the supplied input {@code Future} once the
   * supplied {@code Future} is done, unless this {@code Future} has already been cancelled or set
   * (including "set asynchronously," defined below).
   *
   * <p>If the supplied future is {@linkplain #isDone done} when this method is called and the call

      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

    SettableFuture<String> future = SettableFuture.create();
    FutureTask<Boolean> interruptReporter = untimedInterruptReporter(future, false);

    runNInterruptsTest(times, future, interruptReporter);
  }

  private static void runTimedInterruptsTest(int times)
      throws InterruptedException, ExecutionException, TimeoutException {
    SettableFuture<String> future = SettableFuture.create();

  /**
   * Retrieves the result of a {@code Future} known to be done but uses the {@code get(long,
   * TimeUnit)} overload in order to test that method.
   */
  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 getUninterruptibly(future, 0, SECONDS);
    } catch (TimeoutException e) {

    // 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) {

    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());