code: def connectAsync(self, keepAliveIntervalSecond=600, ackCallback=None):
          
          self._load_callbacks()
          return self._mqtt_core.connect_async(keepAliveIntervalSecond, ackCallback)
docs: **Description**
  
          Connect asynchronously to AWS IoT, with user-specific keepalive interval configuration and CONNACK callback.
  
          **Syntax**
  
          .. code:: python
  
            # Connect to AWS IoT with default keepalive set to 600 seconds and a custom CONNACK callback
            myAWSIoTMQTTClient.connectAsync(ackCallback=my_connack_callback)
            # Connect to AWS IoT with default keepalive set to 1200 seconds and a custom CONNACK callback
            myAWSIoTMQTTClient.connectAsync(keepAliveInternvalSecond=1200, ackCallback=myConnackCallback)
  
          **Parameters**
  
          *keepAliveIntervalSecond* - Time in seconds for interval of sending MQTT ping request.
          Default set to 600 seconds.
  
          *ackCallback* - Callback to be invoked when the client receives a CONNACK. Should be in form
          :code:`customCallback(mid, data)`, where :code:`mid` is the packet id for the connect request
          and :code:`data` is the connect result code.
  
          **Returns**
  
          Connect request packet id, for tracking purpose in the corresponding callback.