/** * @param Event $event * @return string * @throws UnknownEventException */ private function serizlize(Event $event) { if ($event instanceof CustomerPlacedOrder) { return json_encode(['name' => Events::CUSTOMER_PLACED_ORDER, 'order_id' => $event->orderId(), 'date' => $event->date()->format('Y-m-d H:i:s')]); } throw UnknownEventException::unsupported(get_class($event)); }