@staticmethod
def _subscribe(sub_id, channel, callback, **kwargs):
    """Listen to a queue, notify via callback function.
        :param sub_id: ID for this subscription in the transport layer
        :param channel: Queue name to subscribe to
        :param callback: Function to be called when messages are received
        :param **kwargs: Further parameters for the transport layer. For example
               exclusive: Attempt to become exclusive subscriber to the queue.
               acknowledgement: If true receipt of each message needs to be
                                acknowledged.
        """
    raise NotImplementedError('Transport interface not implemented')
