code: def read(self, count=None, block=None, last_id=None):
          
          key = {self.key: '>' if last_id is None else last_id}
          resp = self.database.xreadgroup(self.group, self._consumer, key, count,
                                          block)
          return resp[0][1] if resp else []
docs: Monitor the stream for new messages within the context of the parent
          :py:class:`ConsumerGroup`.
  
          :param int count: limit number of messages returned
          :param int block: milliseconds to block, 0 for indefinitely.
          :param str last_id: optional last ID, by default uses the special
              token ">", which reads the oldest unread message.
          :returns: a list of (message id, data) 2-tuples.