static function getInstanceByDbObject(kAccessControlAction $dbObject)
 {
     switch ($dbObject->getType()) {
         case accessControlActionType::BLOCK:
             return new KalturaAccessControlBlockAction();
         case accessControlActionType::PREVIEW:
             return new KalturaAccessControlPreviewAction();
         default:
             return KalturaPluginManager::loadObject('KalturaAccessControlAction', $dbObject->getType());
     }
 }
 public function __construct()
 {
     parent::__construct(accessControlActionType::PREVIEW);
 }