static void Main(string[] args) { var productService = new Services.ProductService(); productService.AddProduct( new Model.Options.AddProductOptions() { Id = "123", Price = 13.33M, ProductCategory = Model.ProductCategory.Cameras, Name = "Camera 1" }); productService.UpdateProduct("123", new Model.Options.UpdateProductOptions() { Price = 22.22M }); var customerService = new Services.CustomerService(); customerService.AddCustomer( new Model.Options.AddCustomerOptions() { VatNumber = "107786108", Email = "*****@*****.**" }); var cust1 = customerService.GetCustomerByVatNumber("107786108"); Console.WriteLine($"{cust1.Id} k {cust1.VatNumber}"); customerService.AddCustomer( new Model.Options.AddCustomerOptions() { VatNumber = "107786108", Email = "*****@*****.**" }); var orderService = new Services.OrderService(); orderService.AddNewOrder(new Model.Options.AddOrderOptions() { Id = cust1.Id, Products = productService.ProductsList }); Console.WriteLine($"{cust1.Id} k {cust1.VatNumber}"); Console.ReadLine(); }