### Question:
QueueConfig extends SerializableBase { @JsonIgnore public boolean hasDeadLetterQueue() { return !CollectionUtils.isEmpty(deadLetterQueues); }  void updateTime(); boolean updateRetryCount(int newRetryCount); boolean addDeadLetterQueue(DeadLetterQueue deadLetterQueue); boolean updateVisibilityTimeout(long newTimeOut); boolean updateConcurrency(MinMax<Integer> concurrency); boolean updatePriorityGroup(String priorityGroup); boolean updatePriority(Map<String, Integer> newPriority); @JsonIgnore boolean isDeadLetterQueue(String name); @JsonIgnore boolean hasDeadLetterQueue();  }### Answer:
@Test public void hasDeadLetterQueue() { QueueConfig queueConfig = TestUtils.createQueueConfig("test"); assertFalse(queueConfig.hasDeadLetterQueue()); queueConfig = TestUtils.createQueueConfig("test", "test-dlq"); assertTrue(queueConfig.hasDeadLetterQueue()); }