@Override
    public int drainTo(Collection<? super V> c) {
        return get(drainToAsync(c));
    }
@Test
    public void testDrainToSingle() {
        RBlockingQueue<Integer> queue = getQueue();
        Assertions.assertTrue(queue.add(1));
        Assertions.assertEquals(1, queue.size());
        Set<Integer> batch = new HashSet<Integer>();
        int count = queue.drainTo(batch);
        Assertions.assertEquals(1, count);
        Assertions.assertEquals(1, batch.size());
        Assertions.assertTrue(queue.isEmpty());
    }