@staticmethod<EOL><INDENT>def _unpack_message(msg):<DEDENT>
return json.loads(msg.data)<EOL>
Unpack the data from the message.

        Arguments:
          msg (:py:class:`aiohttp.websocket.Message`): The message to
            unpack.

        Returns:
          :py:class:`dict`: The loaded data.

        Raises:
          :py:class:`AttributeError`: If there is no data attribute.
          :py:class:`json.JSONDecodeError`: If the data isn't valid
            JSON.