Ensures a valid log level

        @param level: the asked for level

def _check_log_level(self, level):
        '''
        Ensures a valid log level

        @param level: the asked for level
        '''
        if level not in list(self.level_dict.keys()):
            self.log_level = 'DEBUG'
            self.logger.warn("Unknown log level '{lev}', defaulting to DEBUG"
                             .format(lev=level))