final CyclicBarrier barrier = new CyclicBarrier(2);
    // we need to make sure the error gets thrown on a different thread.
    ExecutorService service = Executors.newSingleThreadExecutor();
    try {
      final SequentialExecutor executor = new SequentialExecutor(service);
      Runnable errorTask =
          new Runnable() {
            @Override
            public void run() {
              throw new MyError();

    final CyclicBarrier barrier = new CyclicBarrier(2);
    // we need to make sure the error gets thrown on a different thread.
    ExecutorService service = Executors.newSingleThreadExecutor();
    try {
      final SequentialExecutor executor = new SequentialExecutor(service);
      Runnable errorTask =
          new Runnable() {
            @Override
            public void run() {
              throw new MyError();