* Executor, and sequentially such that no two will ever be running at the same time.
 *
 * <p>Tasks submitted to {@link #execute(Runnable)} are executed in FIFO order.
 *
 * <p>The execution of tasks is done by one thread as long as there are tasks left in the queue.
 * When a task is {@linkplain Thread#interrupt interrupted}, execution of subsequent tasks
 * continues. See {@link QueueWorker#workOnQueue} for details.
 *

   * turn, and does not create any threads of its own.
   *
   * <p>After execution begins on a thread from the {@code delegate} {@link Executor}, tasks are
   * polled and executed from a task queue until there are no more tasks. The thread will not be
   * released until there are no more tasks to run.
   *
   * <p>If a task is submitted while a thread is executing tasks from the task queue, the thread

 * cancelled).
 *
 * <p>This class serializes execution of <i>submitted</i> tasks but not any <i>listeners</i> of
 * those tasks.
 *
 * <p>Submitted 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 #submit} and
 * {@link #submitAsync} that submitted those tasks had.
 *

  private static class FakeExecutor implements Executor {
    Queue<Runnable> tasks = Queues.newArrayDeque();

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

    boolean hasNext() {
      return !tasks.isEmpty();
    }

    void runNext() {
      assertTrue("expected at least one task to run", hasNext());
      tasks.remove().run();
    }

    void runAll() {

   *   <li>When you reduce the number of buckets, you can accept that the most recently added
   *       buckets will be removed first. More concretely, if you are dividing traffic among tasks,
   *       you can decrease the number of tasks from 15 and 10, killing off the final 5 tasks, and
   *       {@code consistentHash} will handle it. If, however, you are dividing traffic among

  private static class FakeExecutor implements Executor {
    Queue<Runnable> tasks = Queues.newArrayDeque();

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

    boolean hasNext() {
      return !tasks.isEmpty();
    }

    void runNext() {
      assertTrue("expected at least one task to run", hasNext());
      tasks.remove().run();
    }

    void runAll() {

    ExecutorService delegate = mock(ExecutorService.class);
    ListeningExecutorService service = listeningDecorator(delegate);
    Runnable task =
        new Runnable() {
          @Override
          public void run() {}
        };
    service.execute(task);
    verify(delegate).execute(task);
  }

  public void testListeningDecorator_scheduleSuccess() throws Exception {

   * identify deadlocks.
   */
  @VisibleForTesting
  static final class Blocker extends AbstractOwnableSynchronizer implements Runnable {
    private final InterruptibleTask<?> task;

    private Blocker(InterruptibleTask<?> task) {
      this.task = task;
    }

    @Override
    public void run() {}

    private void setOwner(Thread thread) {
      super.setExclusiveOwnerThread(thread);
    }

    assertThat(exceptions).isEmpty();
  }

  private static List<Throwable> runThreadsAndReturnExceptions(int numThreads, Runnable task) {
    List<Thread> threads = new ArrayList<>(numThreads);
    final List<Throwable> exceptions = new ArrayList<>(numThreads);
    for (int i = 0; i < numThreads; i++) {
      Thread thread = new Thread(task);
      thread.setUncaughtExceptionHandler(

    ExecutorService delegate = mock(ExecutorService.class);
    ListeningExecutorService service = listeningDecorator(delegate);
    Runnable task =
        new Runnable() {
          @Override
          public void run() {}
        };
    service.execute(task);
    verify(delegate).execute(task);
  }

  public void testListeningDecorator_scheduleSuccess() throws Exception {