code: def configureLastWill(self, topic, payload, QoS, retain=False):
          
          self._mqtt_core.configure_last_will(topic, payload, QoS, retain)
docs: **Description**
  
          Used to configure the last will topic, payload and QoS of the client. Should be called before connect.
  
          **Syntax**
  
          .. code:: python
  
            myAWSIoTMQTTClient.configureLastWill("last/Will/Topic", "lastWillPayload", 0)
  
          **Parameters**
  
          *topic* - Topic name that last will publishes to.
  
          *payload* - Payload to publish for last will.
  
          *QoS* - Quality of Service. Could be 0 or 1.
  
          **Returns**
  
          None