protected function _extractPassParams()
    {
        if (!empty($this->controller->filterPassParams[$this->action])) {
            foreach ($this->controller->filterPassParams[$this->action] as $key) {
                if (!empty($this->request->getParam($key))) {
                    $this->_passParams[$key] = $this->request->getParam($key);
                }
            }
        }
    }