Handle a subscribe response.

        :param data: Payload.
        :returns: State (ON/OFF)

def _subscribe_resp(self, data):
        """ Handle a subscribe response.

        :param data: Payload.
        :returns: State (ON/OFF)
        """
        if _is_subscribe_response(data):
            status = bytes([data[23]])
            _LOGGER.debug("Successfully subscribed to %s, state: %s",
                          self.host, ord(status))
            return status