@Test
public void orderedSlowPath() {

    TestSubscriber<Integer> ts = new TestSubscriber<Integer>(1);
    Disposable d = Disposables.empty();
    QueueDrainSubscriber<Integer, Integer, Integer> qd = createOrdered(ts, d);
    ts.onSubscribe(new BooleanSubscription());
    qd.enter();
    qd.onNext(1);
    ts.assertEmpty();
}