private static final class TestCallable implements AsyncCallable<@Nullable Void> {

    private final ListenableFuture<@Nullable Void> future;
    private boolean called = false;

    private TestCallable(ListenableFuture<@Nullable Void> future) {
      this.future = future;
    }

    @Override
    public ListenableFuture<@Nullable Void> call() throws Exception {
      called = true;
      return future;
    }
  }

    implements ListenableFuture<V> {

  static final boolean GENERATE_CANCELLATION_CAUSES = false;

  /**
   * Tag interface marking trusted subclasses. This enables some optimizations. The implementation
   * of this interface must also be an AbstractFuture and must not override or expose for overriding
   * any of the public methods of ListenableFuture.
   */

   * #setFuture(ListenableFuture)}.
   */
  private static final class AsyncTransformFuture<
          I extends @Nullable Object, O extends @Nullable Object>
      extends AbstractTransformFuture<
          I, O, AsyncFunction<? super I, ? extends O>, ListenableFuture<? extends O>> {
    AsyncTransformFuture(

  private static final class TestCallable implements AsyncCallable<@Nullable Void> {

    private final ListenableFuture<@Nullable Void> future;
    private boolean called = false;

    private TestCallable(ListenableFuture<@Nullable Void> future) {
      this.future = future;
    }

    @Override
    public ListenableFuture<@Nullable Void> call() throws Exception {
      called = true;
      return future;
    }
  }

  }

  FluentFuture() {}

  /**
   * Converts the given {@code ListenableFuture} to an equivalent {@code FluentFuture}.
   *
   * <p>If the given {@code ListenableFuture} is already a {@code FluentFuture}, it is returned
   * directly. If not, it is wrapped in a {@code FluentFuture} that delegates all calls to the
   * original {@code ListenableFuture}.
   */

   * {@link Callable#call()} will not be invoked.
   */
  public <T extends @Nullable Object> ListenableFuture<T> submit(
      Callable<T> callable, Executor executor) {
    checkNotNull(callable);
    checkNotNull(executor);
    return submitAsync(
        new AsyncCallable<T>() {
          @Override
          public ListenableFuture<T> call() throws Exception {
            return immediateFuture(callable.call());
          }

   *             incomplete and the {@code ListenableFuture} later completes normally, the
   *             listener runs in the thread that completes the {@code ListenableFuture}.
   *         <li>When a listener is attached to a {@code ListenableFuture} and the {@code
   *             ListenableFuture} gets cancelled, the listener runs immediately in the thread that

                } catch (Throwable t) {
                  throwableFromOtherThread.set(t);
                }
              }
            });

    otherThread.start();

    ListenableFuture<?> future = executor.submit(incrementTask);
    assertTrue(future.isDone());
    assertListenerRunImmediately(future);
    assertEquals(1, threadLocalCount.get().intValue());
    otherThread.join(1000);

  }

  public void testSetFuture_misbehavingFutureThrows() throws Exception {
    SettableFuture<String> future = SettableFuture.create();
    ListenableFuture<String> badFuture =
        new ListenableFuture<String>() {
          @Override
          public boolean cancel(boolean interrupt) {
            return false;
          }

          @Override

                } catch (Throwable t) {
                  throwableFromOtherThread.set(t);
                }
              }
            });

    otherThread.start();

    ListenableFuture<?> future = executor.submit(incrementTask);
    assertTrue(future.isDone());
    assertListenerRunImmediately(future);
    assertEquals(1, threadLocalCount.get().intValue());
    otherThread.join(1000);