public IActionResult GetProductsToXml(int productId)
        {
            var products        = _productRepo.Products;
            var getProducts     = ViewModelHelper.GetProducts(products);
            var selectedProduct = getProducts.FirstOrDefault(x => x.Id.Equals(productId));

            if (productId == 0)
            {
                return(Ok(getProducts));
            }
            else
            {
                return(Ok(selectedProduct));
            }
        }
        public IActionResult GetProductsToJson(int productId)
        {
            var products        = _productRepo.Products;
            var getProducts     = ViewModelHelper.GetProducts(products);
            var selectedProduct = getProducts.FirstOrDefault(x => x.Id.Equals(productId));

            if (productId == 0)
            {
                var productJson = JsonConvert.SerializeObject(getProducts);
                var bytes       = Encoding.UTF8.GetBytes(productJson);
                return(File(bytes, "application/octet-stream", "products.json"));
            }
            else
            {
                var selectedProductJson = JsonConvert.SerializeObject(selectedProduct);
                var bytes = Encoding.UTF8.GetBytes(selectedProductJson);
                return(File(bytes, "application/octet-stream", "product_" + productId + ".json"));
            }
        }