public void OrderProductNumber_IsReturned_WhenOrderDetailsAdded()
        {
            //Arrange
            OrderFunctionality o10 = new OrderFunctionality();
            OrderDetails       od3 = new OrderDetails("REF-000-000-01", "REF-000-001", "P0000", 1);

            o10.NewOrderDetails(od3);

            //Act
            int i = o10.OrderProducts("REF-000-000-01");

            //Assert
            Assert.AreEqual(o10.OrderProductNumber(i), "P0000");
        }