public Design_RecentProductsPageViewModel()
        {
            var repository = new DemoProductRepository();
            var products   = repository.GetProducts().Result;

            this.RecentProducts = new BindableCollection <Product>(products);
        }
        public Design_ProductsByCategoryPageViewModel()
        {
            var repository = new DemoProductRepository();
            var products   = repository.GetProducts().Result;
            var category   = repository.GetCategories().Result;

            this.CategoriesAndProducts = new BindableCollection <object>(category.ChildCategories.Union <object>(products));

            this.DisplayCategory = category;
        }