}

  static final class SlowChannel extends AbstractInterruptibleChannel {
    final CountDownLatch exitClose = new CountDownLatch(1);

    @Override
    protected void implCloseChannel() {
      Uninterruptibles.awaitUninterruptibly(exitClose);
    }

    void doBegin() {
      super.begin();
    }
  }

  }

  static final class SlowChannel extends AbstractInterruptibleChannel {
    final CountDownLatch exitClose = new CountDownLatch(1);

    @Override
    protected void implCloseChannel() {
      Uninterruptibles.awaitUninterruptibly(exitClose);
    }

    void doBegin() {
      super.begin();
    }
  }