public async Task <IActionResult> Edit(int?id, CancellationToken cancellationToken)
        {
            var order = await OrderService.Get(id, cancellationToken);

            var orderItems = await OrderItemsService.GetAllForOrder(order.Id, cancellationToken);

            var showModel = ShowViewModel.Create(order, orderItems);

            ViewBag.Providers = await ProviderService.GetAll(cancellationToken);

            return(View(showModel));
        }
        public async Task <IActionResult> Show(int?id, CancellationToken cancellationToken)
        {
            if (id == null)
            {
                return(RedirectToAction("Index"));
            }
            var order = await OrderService.Get(id, cancellationToken);

            var orderItems = await OrderItemsService.GetAllForOrder(order.Id, cancellationToken);

            var showModel = ShowViewModel.Create(order, orderItems);

            return(View(showModel));
        }