public function delete()
 {
     $thumbnail = $this->getThumbnail();
     if ($thumbnail && $thumbnail->exists()) {
         $thumbnail->delete();
     }
     parent::delete();
 }
 /**
  * Also takes care of deleting the associated thumbnails of this image
  *
  * @see sfSympalAssetObject::delete()
  */
 public function delete()
 {
     foreach ($this->getAllThumbnails() as $thumbnail) {
         $thumbnail->delete();
     }
     parent::delete();
 }