public static ShoppingCart GetCart(UnicornStoreContext db, HttpContext context) => GetCart(db, GetCartId(context));
public static ShoppingCart GetCart(UnicornStoreContext db, string cartId) => new ShoppingCart(db, cartId);
private ShoppingCart(UnicornStoreContext dbContext, string id) { _dbContext = dbContext; _shoppingCartId = id; }