Log generic message

        :param string message: the message to log
        :param string severity: the message severity
        :rtype: datetime

def _log(self, message, severity=Logger.DEBUG):
        """
        Log generic message

        :param string message: the message to log
        :param string severity: the message severity
        :rtype: datetime
        """
        return self.logger.log(message, severity, self.TAG)