protected function extractParamNames($pattern, array $values) { $key = $this->keyPrefix . ':' . $pattern . ':' . $this->stateKey; $item = $this->pool->getItem($key); if (!$item->isHit()) { $item->set(parent::extractParamNames($pattern, $values)); $item->expiresAfter($this->ttl); $this->pool->save($item); } return $item->get(); }