public void ProceedCheckOutTest()
{
string id = "item0";
int initStock = _itemInfo.GetItemStock(id);
_itemOrder.AddToOrder(id);
_itemOrder.UpdateQuantity(0, 5);
_itemOrder.ProceedCheckOut();
Assert.AreEqual(0, _itemOrder.GetTotalPrice());
Assert.AreEqual(initStock - 5, _itemInfo.GetItemStock(id));
}