private function getHooplaCover($id)
 {
     require_once ROOT_DIR . '/RecordDrivers/HooplaDriver.php';
     $driver = new HooplaRecordDriver($id);
     /** @var File_MARC_Data_Field[] $linkFields */
     $linkFields = $driver->getMarcRecord()->getFields('856');
     foreach ($linkFields as $linkField) {
         if ($linkField->getIndicator(1) == 4 && $linkField->getIndicator(2) == 2) {
             $coverUrl = $linkField->getSubfield('u')->getData();
             return $this->processImageURL($coverUrl, true);
         }
     }
     return false;
 }