/**
  *
  * @return ActionStack
  */
 public static function getInstance()
 {
     if (null === self::$_instance) {
         self::$_instance = new self();
     }
     return self::$_instance;
 }
 public function setResponse(Response $response)
 {
     $this->_response = $response;
     ActionStack::getInstance()->setResponse($response);
 }
 /**
  * Override to gain pre dispatch logic.
  * Note:
  * The action could be skipped by fowarding from here based on some 
  * test.
  */
 protected function preDispatch()
 {
     $stack = ActionStack::getInstance();
 }