def ping_pong(self):
        """
            Official Handshake with the grading service
            Send a PING
            and wait for PONG
            If not PONG, raise error
        """
        _request = {}
        _request['type'] = messages.OSIM_RL.PING
        _request['payload'] = {}
        _response = self._blocking_request(_request)
        if _response['type'] != messages.OSIM_RL.PONG:
            raise Exception("Unable to perform handshake with the redis service. Expected PONG; received {}".format(json.dumps(_response)))
        else:
            return True

            Official Handshake with the grading service
            Send a PING
            and wait for PONG
            If not PONG, raise error
        
osim/redis/client.py