public function url($url, $title, $order = 0, $attributes = array())
    {
        if (func_num_args() == 3) {
            $arguments = func_get_args();

            return $this->add([
                'url' => array_get($arguments, 0),
                'title' => array_get($arguments, 1),
                'attributes' => array_get($arguments, 2)
            ]);
        }

        return $this->add(compact('url', 'title', 'order', 'attributes'));
    }