public function toArray(array $keys = [])
    {
        $data = parent::toArray($keys);

        if (in_array('url', $keys) || empty($keys)) {
            $data['url'] = $this->getUrl();
        }

        if (in_array('is_selected', $keys) || empty($keys)) {
            $data['is_selected'] = (bool) $this->getIsSelected();
        }

        return $data;
    }