public function getStackUrl(
      $image,
      $stack,
      $format = 'jpg',
      $seo = null,
      $seoLanguage = 'de'
    ) {
        if (null == $image) {
            return '';
        }
        $image = $this->getImageObject($image);

        if (!$hash = self::getHashMaybeUpload($image)) {
            return '';
        }
        if (null === $seo) {
            return $this->generateRokkaUrlWithImage($hash, $stack, $format, $image, $seoLanguage);
        }

        return $this->generateRokkaUrl($hash, $stack, $format, $seo, $seoLanguage);
    }