public static function addTariffPublic($em, $parameters)
 {
     $em->getConnection()->beginTransaction();
     try {
         $tariff = new Tariff();
         $tariff->setName($parameters->name);
         $tariff->setActive(TRUE);
         $tariff->setDiscount($parameters->discount);
         $tariff->setPayment(0);
         $tariff->setSquaring(1);
         $tariff->setCreated(new \DateTime());
         $tariff->setActivated(new \DateTime());
         $tariff->setPage($parameters->page);
         $em->persist($tariff);
         $em->flush();
         $tariff->createTariffServices($em, $parameters);
         $tariff->createTariffPrices($em, $parameters);
         $em->getConnection()->commit();
         return $tariff;
     } catch (Exception $e) {
         $em->getConnection()->rollback();
         throw $e;
     }
 }