public void OrderTotalIsZero_IsReturned_WhenQuantityIsZero()
        {
            //Arrange
            OrderFunctionality o8  = new OrderFunctionality();
            OrderDetails       od1 = new OrderDetails("REF-000-000-01", "REF-000-001", "P0001", 0);

            o8.NewOrderDetails(od1);
            Product product1 = new Product("1", "Test1", 0.01m);

            o8.NewProduct(product1);
            //Act
            //Assert
            Assert.AreEqual(o8.OrderTotal("REF-000-000-01", "1"), 0.00m);
        }