public static function pull($arr, $name, $type = null)
    {
        $ret = [];
        if ($type == self::GETTER) {
            $method = 'get' . $name;
            foreach ($arr as $elem) {
                $ret[] = $elem->$method();
            }
        } elseif ($type == self::OBJ) {
            foreach ($arr as $elem) {
                $ret[] = $elem->$name;
            }
        } else {
            foreach ($arr as $elem) {
                $ret[] = $elem[$name];
            }
        }
        return $ret;
    }