/** Use {@link MoreExecutors#newSequentialExecutor} */
  SequentialExecutor(Executor executor) {
    this.executor = Preconditions.checkNotNull(executor);
  }

  /**
   * Adds a task to the queue and makes sure a worker thread is running.
   *
   * <p>If this method throws, e.g. a {@code RejectedExecutionException} from the delegate executor,
   * execution of tasks will stop until a call to this method is made.
   */
  @Override

  /** Use {@link MoreExecutors#newSequentialExecutor} */
  SequentialExecutor(Executor executor) {
    this.executor = Preconditions.checkNotNull(executor);
  }

  /**
   * Adds a task to the queue and makes sure a worker thread is running.
   *
   * <p>If this method throws, e.g. a {@code RejectedExecutionException} from the delegate executor,
   * execution of tasks will stop until a call to this method is made.
   */
  @Override

    assertEquals(0, numCalls.get());
    reject.set(false);
    executor.execute(task);
    assertEquals(1, numCalls.get());
  }

  /*
   * Under Android, MyError propagates up and fails the test?
   *
   * TODO(b/218700094): Does this matter to prod users, or is it just a feature of our testing

   *     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);
  }

  /**

      /** The future that represents the next execution of this task. */
      @GuardedBy("lock")
      private @Nullable SupplantableFuture cancellationDelegate;

      ReschedulableCallable(
          AbstractService service, ScheduledExecutorService executor, Runnable runnable) {
        this.wrappedRunnable = runnable;
        this.executor = executor;
        this.service = service;
      }

  }

  /**
   * 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;
    }
  }

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

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

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

   */
  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

  }

  /**
   * Adds a listener that will be called using the given executor when events are later {@link
   * #enqueue enqueued} and {@link #dispatch dispatched}.
   */
  public void addListener(L listener, Executor executor) {
    checkNotNull(listener, "listener");
    checkNotNull(executor, "executor");
    listeners.add(new PerListenerQueue<>(listener, executor));
  }

  /**

        SmbTransportPoolImpl pool = new SmbTransportPoolImpl();
        pool.setMaxPoolSize(100);

        int threadCount = 20;
        int operationsPerThread = 100;
        ExecutorService executor = Executors.newFixedThreadPool(threadCount);
        CountDownLatch startLatch = new CountDownLatch(1);
        CountDownLatch endLatch = new CountDownLatch(threadCount);

        AtomicLong totalTime = new AtomicLong(0);