public DummyScheduledThreadPoolExecutor() {
        super(1);
      }
    }

    public static final class DummyCountDownLatch extends CountDownLatch {
      public DummyCountDownLatch() {
        super(0);
      }
    }

    public static final class DummyRunnable implements Runnable, Serializable {
      @Override
      public void run() {}
    }

      public DummyScheduledThreadPoolExecutor() {
        super(1);
      }
    }

    public static final class DummyCountDownLatch extends CountDownLatch {
      public DummyCountDownLatch() {
        super(0);
      }
    }

    public static final class DummyRunnable implements Runnable, Serializable {
      @Override
      public void run() {}
    }