public void TestInitialize()
        {
            _securityProvider = Substitute.For<IWebSecurityProvider>();
            _session = Substitute.For<ISessionProvider>();
            _carts = Substitute.For<ICartRepository>();
            _shoppingCartFactory = Substitute.For<IShoppingCartFactory>();

            _shoppingCart = new ShoppingCart(Substitute.For<IUnitOfWork>(), _carts,
                                    Substitute.For<IAlbumsRepository>(), Substitute.For<IOrderDetailRepository>());

            _carts.Get().Returns(new List<Cart> { new Cart { CartId = "CartA" }, new Cart { CartId = "CartB" } }.AsQueryable());

            _shoppingCartFactory.GetCart(null as HttpContextBase).Returns(_shoppingCart);

        }
 public ShoppingCart GetCart(HttpContextBase context)
 {
     var cart = new ShoppingCart(_unitOfWork, _carts, _albums, _orderDetails);
     cart.ShoppingCartId = cart.GetCartId(context);
     return cart;
 }