public async Task<ActionResult> AddOrUpdateCartShipment(ShipmentUpdateModel shipment)
{
EnsureThatCartExist();
//Need lock to prevent concurrent access to same cart
using (await AsyncLock.GetLockByKey(GetAsyncLockCartKey(WorkContext.CurrentCart.Id)).LockAsync())
{
await _cartBuilder.AddOrUpdateShipmentAsync(shipment);
await _cartBuilder.SaveAsync();
}
return new HttpStatusCodeResult(HttpStatusCode.OK);
}