Stopwatch timer = Stopwatch.createStarted();

      int drained = drain(q, newArrayList(), 2, 10, MILLISECONDS, interruptibly);
      assertThat(drained).isAtMost(1);

      assertThat(timer.elapsed(MILLISECONDS)).isAtLeast(10L);

      // If even the first one wasn't there, clean up so that the next test doesn't see an element.
      producerThread.cancel(true);
      producer.doneProducing.await();

      Stopwatch timer = Stopwatch.createStarted();

      int drained = drain(q, newArrayList(), 2, 10, MILLISECONDS, interruptibly);
      assertThat(drained).isAtMost(1);

      assertThat(timer.elapsed(MILLISECONDS)).isAtLeast(10L);

      // If even the first one wasn't there, clean up so that the next test doesn't see an element.
      producerThread.cancel(true);
      producer.doneProducing.await();