Convert message to JSON and send it to the client with token

def raw_message_to(self, token, message):
        """Convert message to JSON and send it to the client with token"""
        if token not in self._clients:
            log.critical("Client with token '{0}' not found!".format(token))
            return
        client = self._clients[token]
        try:
            client.write_message(message)
        except (AttributeError, tornado.websocket.WebSocketClosedError):
            log.error("Lost connection to client '{0}'".format(client))
        else:
            print("Sent {0} bytes.".format(len(message)))