private static function _toArray($data, $recursion = false)
    {
        $tmp  = array();
        $data = (array) $data;
        foreach ($data as $k => $v) {
            $v = (array) $v;
            if (isset($v[0]) && is_string($v[0])) {
                $tmp[$k] = $v[0];
            } else {
                $tmp[$k] = self::_toArray($v, true);
            }
        }
        return $tmp;
    }