protected function unsetOpt(array &$opts, $mapperString)
    {
        $ploded = explode('.', $mapperString);
        $arr = &$opts;
        while ($curr = array_shift($ploded)) {
            if (isset($arr[$curr])) {
                if (is_array($arr[$curr])) {
                    $arr = &$arr[$curr];
                } else {
                    unset($arr[$curr]);
                }
            }
        }
    }