code: async def _on_message(self, channel, body, envelope, properties) -> None:
          
  
          subscribers = self._get_subscribers(envelope.routing_key)
          if not subscribers:
              logger.debug("No route for message with key '%s'", envelope.routing_key)
              return
  
          body = self._serializer.deserialize(body)
  
          for subscriber in subscribers:
              # Check later if ensure_future can be applied here
              await subscriber.on_message(body, envelope.routing_key)
  
          await self._channel.basic_client_ack(envelope.delivery_tag)
docs: Fires up when message is received by this consumer.
  
          :param channel: Channel, through which message is received
          :param body: Body of the message (serialized).
          :param envelope: Envelope object with message meta
          :type envelope: aioamqp.Envelope
          :param properties: Properties of the message
          :return: Coroutine object with result of message handling operation