Updated Order Created Apply

Order.ts

class Order {
  protected whenOrderCreated(event: OrderCreated): void {
        this._items = event.items;
        this._status = OrderStatus.OPEN;
        this._amount = event.amount;
        this._destination = event.destination;
        this._customerId = event.customerId;

        // New code
        this.deliveryMethod = event.deliveryMethod;
    }
}