public async Task <Unit> Handle(UpdateBasketCommand request, CancellationToken cancellationToken)
{
var products = request.Items.Select(x => new KeyValuePair <int, int>(x.ProductId, x.Quantity)).ToList();
await _mediator.Publish(new CheckStockEvent(products), cancellationToken);
var basket = new Basket(request.CustomerId);
basket.AddBasketItems(request.Items.Select(x => x.Map <BasketItem>()).ToList());
await _basketRepository.UpdateBasketAsync(basket);
return(Unit.Value);
}