@Test
public void testGet() {

  GuardedQueue g = new GuardedQueue();
  ExecutorService executorService = Executors.newFixedThreadPool(2);
  executorService.submit(() -> value = g.get());
  executorService.submit(() -> g.put(Integer.valueOf(10)));
  executorService.shutdown();
  try {
    executorService.awaitTermination(30, TimeUnit.SECONDS);
  } catch (InterruptedException e) {
    e.printStackTrace();
  }
  Assert.assertEquals(Integer.valueOf(10), value);
}