protected static function fetch_helper($table, $classname, $params) {
        if ($instances = self::fetch_all_helper($table, $classname, $params)) {
            if (count($instances) > 1) {
                // we should not tolerate any errors here - problems might appear later
                print_error('morethanonerecordinfetch','debug');
            }
            return reset($instances);
        } else {
            return false;
        }
    }