public function afterSave()
 {
     MediaUpload::deleteAll(['owner_class' => $this->ownerClassName, 'owner_id' => $this->owner->primaryKey]);
     foreach ($this->newUploads as $media_id) {
         $mediaUpload = new MediaUpload(['media_id' => $media_id, 'owner_class' => $this->ownerClassName, 'owner_id' => $this->owner->primaryKey]);
         $mediaUpload->save();
     }
     $this->uploads = $this->newUploads;
 }