code: def configureLastWill(self, topic, payload, QoS):
          
          # AWSIoTMQTTClient.configureLastWill(srcTopic, srcPayload, srcQos)
          self._AWSIoTMQTTClient.configureLastWill(topic, payload, QoS)
docs: **Description**
  
          Used to configure the last will topic, payload and QoS of the client. Should be called before connect. This is a public
          facing API inherited by application level public clients.
  
          **Syntax**
  
          .. code:: python
  
            myShadowClient.configureLastWill("last/Will/Topic", "lastWillPayload", 0)
            myJobsClient.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