public static void SerializeTest(OrderService os)
 {
     try
     {
         os.ExportToXml("test.xml");
         OrderService os2 = new OrderService();
         os2.ImportFromXml("test.xml");
         os2.ExportToXml("test2.xml");
     }
     catch (Exception e)
     {
         Console.WriteLine(e.Message);
     }
 }