public async Task <IActionResult> AddProductInstance(int productId)
        {
            var sessionLunch = _cartRepository.GetOrCreateSessionLunch();
            var result       = await _lunchRepository.AddItemInstanceAsync(sessionLunch.Lunch.LunchId, productId);

            var route = "~/Views/Lunch/ItemDetail.cshtml";

            return(PartialView(route, result));
        }
        public async Task <_Catering> AddItem(int id)
        {
            var catering = _cart.SessionCatering();

            if (catering != null &&
                catering.Items != null &&
                catering.Items.FirstOrDefault(i => i.Item != null && i.Item.ProductId == id) != null)
            {
                await _catering.AddItemInstanceAsync(catering.LunchId, id);
            }
            else
            {
                await _catering.AddItemAsync(catering.LunchId, id);
            }
            catering = _cart.SessionCatering();
            return(catering);
        }