### Question:
AWSIotMqttTopic { public void setQos(AWSIotMqttQos qos) { this.qos = qos; } 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 testSetQos() throws Exception { topicModel.setQos(AWSIotMqttQos.QOS1); assertEquals(AWSIotMqttQos.QOS1, topicModel.getQos()); topicModel.setQos(AWSIotMqttQos.QOS0); }