public function __construct($selector)
 {
     $closure = function (Crawler $crawler) {
         return $crawler->attr('href');
     };
     parent::__construct($selector, $closure);
 }
 public function analyze(Crawler $crawler)
 {
     if ($list = $this->finder->getList($crawler)) {
         $this->repository->push($list);
     }
 }