private function persistNewEvents(ProductReturn $return)
 {
     $createStoredEvent = function ($event, $eventNumber) use($return) {
         return new StoredEvent($return->getAggregateId(), $eventNumber, $event);
     };
     $eventsToStore = array_map($createStoredEvent, $return->getNewEvents(), $this->getNewEventNumbers($return));
     array_walk($eventsToStore, [$this->registry->getManager(), 'persist']);
     $this->registry->getManager()->flush();
 }