ProductImage::model PHP Method

    public static function model($className = __CLASS__)
    {
        return parent::model($className);
    }

 public function loadModel($id)
 {
     if (($model = ProductImage::model()->findByPk($id)) === null) {
         throw new CHttpException(404, 'Страница не найдена');
     }
     return $model;
 }