def json_record(self, message, extra, record):
        """Prepares a JSON payload which will be logged.

        Override this method to change JSON log format.

        :param message: Log message, e.g., `logger.info(msg='Sign up')`.
        :param extra: Dictionary that was passed as `extra` param
            `logger.info('Sign up', extra={'referral_code': '52d6ce'})`.
        :param record: `LogRecord` we got from `JSONFormatter.format()`.
        :return: Dictionary which will be passed to JSON lib.

        """
        extra['message'] = message
        if 'time' not in extra:
            extra['time'] = datetime.utcnow()

        if record.exc_info:
            extra['exc_info'] = self.formatException(record.exc_info)

        return extra