[Test] //
        public void GetTotalValueFoTwoSameProductA()
        {
            //Arrange

            PointOfSaleTerminal pointOfSale = new PointOfSaleTerminal();
            Product             product     = new Product("A", 2, 1.25);

            //Act
            pointOfSale.ScanProduct(product);

            //Assert

            Assert.AreEqual(2.5, pointOfSale.DiscountForA("A"));
        }