/**
  * Output product description as an ATOM feed
  */
 public function toATOM()
 {
     /*
      * Initialize ATOM feed
      */
     $atomFeed = new RestoATOMFeed($this->description['properties']['id'], $this->context->title, $this->getATOMSubtitle());
     /*
      * Set collection elements
      */
     $atomFeed->setCollectionElements($this->description['properties']);
     /*
      * Add one entry per product
      */
     $atomFeed->addEntries($this->restoFeatures, $this->context);
     /*
      * Return ATOM result
      */
     return $atomFeed->toString();
 }