protected function findRedirectLinkInHeader(&$http_header)
  {
    PHPCrawlerBenchmark::start("checking_for_redirect_link");
    
    // Get redirect-URL or link from header
    $redirect_link = PHPCrawlerUtils::getRedirectURLFromHeader($http_header);
    
    // Add redirect-URL to linkcache
    if ($redirect_link != null)
    {
      $this->addLinkToCache($redirect_link, "", "", true);
    }
    
    PHPCrawlerBenchmark::stop("checking_for_redirect_link");
  }