public WriteShoppingCartRequestHandler(IShoppingCartRepository shoppingCartRepository,
                                        IItemShoppingCartRepository itemShoppingCartRepository, IAspNetUser user)
 {
     _shoppingCartRepository     = shoppingCartRepository;
     _itemShoppingCartRepository = itemShoppingCartRepository;
     _customerId = Guid.Parse(user.GetId());
 }
        public async Task <RequestResult> Handle(GetShoppingCartRequest request, CancellationToken cancellationToken)
        {
            var customerId   = Guid.Parse(_user.GetId());
            var shoppingCart = await _repository.GetShoppingCartByCustomerIdAsync(customerId) ?? new CustomerShoppingCart(customerId);

            return(new RequestResult {
                Content = shoppingCart
            });
        }