code: def ack(self, delivery_tag=0, multiple=False):
          
          if not compatibility.is_integer(delivery_tag):
              raise AMQPInvalidArgument('delivery_tag should be an integer')
          elif not isinstance(multiple, bool):
              raise AMQPInvalidArgument('multiple should be a boolean')
          ack_frame = specification.Basic.Ack(delivery_tag=delivery_tag,
                                              multiple=multiple)
          self._channel.write_frame(ack_frame)
docs: Acknowledge Message.
  
          :param int/long delivery_tag: Server-assigned delivery tag
          :param bool multiple: Acknowledge multiple messages
  
          :raises AMQPInvalidArgument: Invalid Parameters
          :raises AMQPChannelError: Raises if the channel encountered an error.
          :raises AMQPConnectionError: Raises if the connection
                                       encountered an error.
  
          :return: