/**
  * Updates UrlInformation with new values if they are not already set.
  *
  * @param UrlInformation $urlInformation The value object to update.
  * @param object         $object         The sitemap element to get values from.
  * @param string         $sitemap        Name of the sitemap being built.
  */
 public function guessValues(UrlInformation $urlInformation, $object, $sitemap)
 {
     if ($object instanceof SitemapPropertiesReadInterface) {
         if (!$urlInformation->getChangeFrequency() && ($period = $object->getUpdatePeriod())) {
             $urlInformation->setChangeFrequency($period);
         }
         if ($urlInformation->getPriority() === null) {
             $weight = $object->getPageWeight();
             if ($weight !== null) {
                 $urlInformation->setPriority($weight);
             }
         }
     }
 }