}

  /**
   * Returns an {@link Executor} that runs each task executed sequentially, such that no two tasks
   * are running concurrently.
   *
   * <p>{@linkplain Executor#execute executed} tasks have a happens-before order as defined in the
   * Java Language Specification. Tasks execute with the same happens-before order that the function
   * calls to {@link Executor#execute execute()} that submitted those tasks had.
   *

    ClosingFuture<String> closingFuture =
        ClosingFuture.from(executor.submit(Callables.returning(closeable1)))
            .transform(
                (DeferredCloser closer, TestCloseable v) -> {
                  assertThat(v).isSameInstanceAs(closeable1);
                  return "value";
                },
                executor);
    assertThat(getFinalValue(closingFuture)).isEqualTo("value");

      final Executor executor;

      RunnableExecutorPair(Runnable runnable, Executor executor) {
        this.runnable = runnable;
        this.executor = executor;
      }

      void execute() {
        try {
          executor.execute(runnable);
        } catch (RuntimeException e) {
          log.log(
              Level.SEVERE,
              "RuntimeException while executing runnable "

    barrier.await(1, SECONDS);
    assertFalse(executor.isShutdown());
    assertFalse(executor.isTerminated());

    executor.shutdown();
    assertTrue(executor.isShutdown());
    assertThrows(RejectedExecutionException.class, () -> executor.submit(() -> {}));
    assertFalse(executor.isTerminated());

    // WAIT #2
    barrier.await(1, SECONDS);
    assertFalse(executor.awaitTermination(20, MILLISECONDS));

   *     returned future.
   * @param executor Executor to run the function in.
   * @return A future that holds result of the transformation.
   */
  public final <T extends @Nullable Object> FluentFuture<T> transform(
      Function<? super V, T> function, Executor executor) {
    return (FluentFuture<T>) Futures.transform(this, function, executor);
  }

  /**

      assertEquals(Service.State.STOPPING, state());
      shutdownCalled++;
    }

    @Override
    protected Executor executor() {
      return executor;
    }

    @Override
    public void tearDown() throws Exception {
      executor.shutdown();
    }
  }

   *     exception itself.
   * @param executor the executor that runs {@code fallback} if the input fails
   */
  public <X extends Throwable> ClosingFuture<V> catching(
      Class<X> exceptionType, ClosingFunction<? super X, ? extends V> fallback, Executor executor) {
    return catchingMoreGeneric(exceptionType, fallback, executor);
  }

   */
  public static <V extends @Nullable Object> ListenableFuture<V> listenInPoolThread(
      Future<V> future, Executor executor) {
    checkNotNull(executor);
    if (future instanceof ListenableFuture) {
      return (ListenableFuture<V>) future;
    }
    return new ListenableFutureAdapter<>(future, executor);
  }

  /**
   * An adapter to turn a {@link Future} into a {@link ListenableFuture}. This will wait on the

  }

  /**
   * An {@link Executor} wanna-be that simply records the tasks it's given. Arguably the Worst
   * Executor Ever.
   *
   * @author cbiffle
   */
  public static class FakeExecutor implements Executor {
    List<Runnable> tasks = new ArrayList<>();

    @Override
    public void execute(Runnable task) {
      tasks.add(task);
    }

    public List<Runnable> getTasks() {
      return tasks;

      final Executor executor;

      RunnableExecutorPair(Runnable runnable, Executor executor) {
        this.runnable = runnable;
        this.executor = executor;
      }

      void execute() {
        try {
          executor.execute(runnable);
        } catch (RuntimeException e) {
          log.log(
              Level.SEVERE,
              "RuntimeException while executing runnable "