code: def _process_tags(self, tags):
          
          if not tags:
              return []
          return [message.Tag.from_str(x) for x in tags.split(';')]
docs: Process the tags of the message
  
          :param tags: the tags string of a message
          :type tags: :class:`str` | None
          :returns: list of tags
          :rtype: :class:`list` of :class:`message.Tag`
          :raises: None