/** Discounts by category implementation. */
 protected static function byCategory($order, $contact, $apply)
 {
     if (!$contact) {
         return 0;
     }
     $ccdm = new shopContactCategoryDiscountModel();
     return max(0.0, min(100.0, $ccdm->getByContact($contact->getId()))) * $order['total'] / 100.0;
 }