code: def wait_msg(self, event, timeout=None, raises=None):
          
          resp = self.wait_event(event, timeout, raises)
  
          if resp is not None:
              return resp[0]
docs: Wait for a message, similiar to :meth:`.wait_event`
  
          :param event: :class:`.EMsg' or job id
          :param timeout: seconds to wait before timeout
          :type timeout: :class:`int`
          :param raises: On timeout when ``False` returns :class:`None`, else raise :class:`gevent.Timeout`
          :type raises: :class:`bool`
          :return: returns a message or :class:`None`
          :rtype: :class:`None`, or `proto message`
          :raises: ``gevent.Timeout``