public static void SetItemId <T>(T item, int?id) where T : class
        {
            var type = typeof(T);
            var prop = MobileServiceRequestHelper <T> .GetIdProperty();

            prop.SetValue(item, id, null);
        }
        public static int GetItemId <T>(T item) where T : class
        {
            var type = typeof(T);
            var prop = MobileServiceRequestHelper <T> .GetIdProperty();

            var id = (int)prop.GetValue(item, null);

            return(id);
        }