private function _get($cfg/*, ... */) {
        $args = array_slice(func_get_args(), 1);
        if (count($args) === 0)
            return $cfg;
        else {
            if (!is_array($cfg) || !$this->has($args[0], $cfg))
                throw new NotFoundSettingsException($args[0]);
            $args[0] = $cfg[$args[0]];
            return call_user_func_array(array($this, "_get"), $args);
        }
    }