public function getCrawler()
    {
        if (!$this->crawler instanceof Crawler) {
            $this->crawler = new Crawler('', $this->getUri()->toString());
            $this->crawler->addContent(
                $this->getResponse()->getBody()->__toString(),
                $this->getResponse()->getHeaderLine('Content-Type')
            );
        }
        return $this->crawler;
    }