### Question:
TopicUtil { public static String getFailTopicName(String consumerGroupName, String topicName) { return String.format("%s_%s_fail", consumerGroupName, topicName); }  static String getFailTopicName(String consumerGroupName, String topicName);  }### Answer:
@Test public void getFailTopicNameTest() { assertEquals("1_2_fail", TopicUtil.getFailTopicName("1", "2")); }