code: def add_async_receiver(
              self, consumer_group, partition, offset=None, prefetch=300,
              operation=None, keep_alive=30, auto_reconnect=True, loop=None):
          
          path = self.address.path + operation if operation else self.address.path
          source_url = "amqps://{}{}/ConsumerGroups/{}/Partitions/{}".format(
              self.address.hostname, path, consumer_group, partition)
          handler = AsyncReceiver(
              self, source_url, offset=offset, prefetch=prefetch,
              keep_alive=keep_alive, auto_reconnect=auto_reconnect, loop=loop)
          self.clients.append(handler)
          return handler
docs: Add an async receiver to the client for a particular consumer group and partition.
  
          :param consumer_group: The name of the consumer group.
          :type consumer_group: str
          :param partition: The ID of the partition.
          :type partition: str
          :param offset: The offset from which to start receiving.
          :type offset: ~azure.eventhub.common.Offset
          :param prefetch: The message prefetch count of the receiver. Default is 300.
          :type prefetch: int
          :operation: An optional operation to be appended to the hostname in the source URL.
           The value must start with `/` character.
          :type operation: str
          :rtype: ~azure.eventhub.async_ops.receiver_async.ReceiverAsync