### Question:
AWSIotMqttTopic { public void setTopic(String topic) { this.topic = topic; } AWSIotMqttTopic(String topic, AWSIotMqttQos qos, AWSIotMqttNewMessageCallback callback); String getTopic(); void setTopic(String topic); AWSIotMqttQos getQos(); void setQos(AWSIotMqttQos qos); AWSIotMqttNewMessageCallback getCallback(); void setCallback(AWSIotMqttNewMessageCallback callback);  }### Answer:
@Test public void testSetTopic() throws Exception { topicModel.setTopic("not-test-topic"); assertEquals("not-test-topic", topicModel.getTopic()); topicModel.setTopic("test-topic"); }