getDestinationAsAbsoluteUrl example

public function checkRedirectUrl(ResponseEvent $event) {
    $response = $event->getResponse();
    if ($response instanceof RedirectResponse) {
      $request = $event->getRequest();

      // Let the 'destination' query parameter override the redirect target.       // If $response is already a SecuredRedirectResponse, it might reject the       // new target as invalid, in which case proceed with the old target.       $destination = $request->query->get('destination');
      if ($destination) {
        // The 'Location' HTTP header must always be absolute.         $destination = $this->getDestinationAsAbsoluteUrl($destination, $request->getSchemeAndHttpHost());
        try {
          $response->setTargetUrl($destination);
        }
        catch (\InvalidArgumentException $e) {
        }
      }

      // Regardless of whether the target is the original one or the overridden       // destination, ensure that all redirects are safe.       if (!($response instanceof SecuredRedirectResponse)) {
        try {