/**
  * @param SS_HTTPRequest $request
  * @throws SS_HTTPResponse_Exception
  */
 public function onBeforeHTTPError404($request)
 {
     $url = strtolower($this->getUrl($request));
     $oldPage = OldURLRedirect::get_from_url($url);
     // If there's a match, direct!
     if ($oldPage) {
         $response = new SS_HTTPResponse();
         $dest = $oldPage->getRedirectionLink();
         $response->redirect(Director::absoluteURL($dest), $oldPage->getRedirectCode());
         throw new SS_HTTPResponse_Exception($response);
     }
 }