* guaranteed to execute. There is no guarantee, however, that listeners will be executed in the
 * order that they are added.
 *
 * <p>Exceptions thrown by a listener will be propagated up to the executor. Any exception thrown
 * during {@code Executor.execute} (e.g., a {@code RejectedExecutionException} or an exception

      new IteratorOperation() {
        @Override
        public @Nullable Object execute(Iterator<?> iterator) {
          iterator.remove();
          return null;
        }
      };

  private static final IteratorOperation NEXT_METHOD =
      new IteratorOperation() {
        @Override
        public @Nullable Object execute(Iterator<?> iterator) {
          return iterator.next();
        }
      };

   * calls to {@link Executor#execute `execute()`} that submitted those tasks had.
   *
   * <p>The executor uses {@code delegate} in order to {@link Executor#execute execute} each task in
   * 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

      new IteratorOperation() {
        @Override
        public @Nullable Object execute(Iterator<?> iterator) {
          iterator.remove();
          return null;
        }
      };

  private static final IteratorOperation NEXT_METHOD =
      new IteratorOperation() {
        @Override
        public @Nullable Object execute(Iterator<?> iterator) {
          return iterator.next();
        }
      };

  static class ExecutorSpy implements Executor {

    Executor delegate;
    boolean wasExecuted;

    public ExecutorSpy(Executor delegate) {
      this.delegate = delegate;
    }

    @Override
    public void execute(Runnable command) {
      delegate.execute(command);
      wasExecuted = true;
    }
  }

  public void testTransform_Executor() throws Exception {

    @CheckForNull // null only for TOMBSTONE
    final Executor executor;

    // writes to next are made visible by subsequent CAS's on the listeners field
    @CheckForNull Listener next;

    Listener(Runnable task, Executor executor) {
      this.task = task;
      this.executor = executor;
    }

    Listener() {
      this.task = null;
      this.executor = null;
    }
  }

    executor.execute(task);
    return task;
  }

  /**
   * Executes {@code runnable} on the specified {@code executor}, returning a {@code Future} that
   * will complete after execution.
   *
   * @throws RejectedExecutionException if the task cannot be scheduled for execution
   * @since 28.2
   */
  public static ListenableFuture<@Nullable Void> submit(Runnable runnable, Executor executor) {

  static class ExecutorSpy implements Executor {

    Executor delegate;
    boolean wasExecuted;

    public ExecutorSpy(Executor delegate) {
      this.delegate = delegate;
    }

    @Override
    public void execute(Runnable command) {
      delegate.execute(command);
      wasExecuted = true;
    }
  }

  public void testTransform_Executor() throws Exception {

  protected static final boolean expensiveTests = Boolean.getBoolean("jsr166.expensiveTests");

  /**
   * If true, report on stdout all "slow" tests, that is, ones that take more than profileThreshold
   * milliseconds to execute.
   */
  private static final boolean profileTests = Boolean.getBoolean("jsr166.profileTests");

  /**
   * The number of milliseconds that tests are permitted for execution without being reported, when

  protected static final boolean expensiveTests = Boolean.getBoolean("jsr166.expensiveTests");

  /**
   * If true, report on stdout all "slow" tests, that is, ones that take more than profileThreshold
   * milliseconds to execute.
   */
  private static final boolean profileTests = Boolean.getBoolean("jsr166.profileTests");

  /**
   * The number of milliseconds that tests are permitted for execution without being reported, when