static void Main(string[] args)
{
OrderService orderService = new OrderService();
OrderDetails detail1 = new OrderDetails("iphone", 5000, 1);
OrderDetails detail2 = new OrderDetails("ipad", 10000, 1);
List <OrderDetails> details = new List <OrderDetails> {
detail1, detail2
};
Orders order1 = new Orders("20181129001", "Jack", "13811111111", details);
Orders order2 = new Orders("20181129001", "Tom", "13811111111", details);
orderService.AddOrders2(order1);
orderService.ChangeOrder(order2);
List <Orders> orders = orderService.SearchOrder("Tom");
orders.ForEach(o => Console.WriteLine($"{o.orderNumber},{o.theCustomer}"));
}