AndroidPayQuickstart.WalletUtil.calculateCartTotal C# (CSharp) Method

        private static String calculateCartTotal(List<LineItem> lineItems) 
        {
            BigDecimal cartTotal = BigDecimal.Zero;

            // Calculate the total price by adding up each of the line items
            foreach (var lineItem in lineItems) {
                BigDecimal lineItemTotal = lineItem.TotalPrice == null ?
                    new BigDecimal(lineItem.UnitPrice)
                    .Multiply (new BigDecimal(lineItem.Quantity)) :
                    new BigDecimal(lineItem.TotalPrice);

                cartTotal = cartTotal.Add (lineItemTotal);
            }

            return cartTotal.SetScale (2, RoundingMode.HalfEven).ToString ();
        }