protected function _defaultData($content)
    {
        $content = @unserialize($content);
        if (empty($content) || !is_a($content, \stdClass::class)) {
            $content = new \stdClass;
        }
        $content->selected = isset($content->selected) ? $content->selected : '';
        $content->price = isset($content->price) ? $content->price : '';
        return $content;
    }