public async Task <Cart> Handle(Query query, CancellationToken cancellationToken)
            {
                var cart = await cartsRepository.GetByUserId(query.UserId);

                if (cart == null)
                {
                    var cartCreatedEvent = new CartCreatedEvent(query.UserId);

                    cart = new Cart(cartCreatedEvent);
                }

                throw new Exception();
            }