public void Given_UserID_and_RideList_Should_Return_InvoiceSummary()
        {
            List <RideDetails> user1Details = new List <RideDetails>();

            user1Details.Add(new RideDetails(20, 15));
            user1Details.Add(new RideDetails(10, 10));
            user1Details.Add(new RideDetails(5, 5));
            user1Details.Add(new RideDetails(15, 10));

            rideRepo.AddUser("user1", user1Details);

            try
            {
                invoiceGenerator.MultipleTripFareCalculationList("user1", InvoiceGenerator.RideType.NORMAL);
                string actualInvoice = invoiceGenerator.GenerateInvoiceSummary();

                Assert.AreEqual("4,450,112.5", actualInvoice);
            }
            catch (InvoiceException e)
            {
                Assert.AreEqual(InvoiceException.ExceptionType.INVALID_USER_ID, e.type);
            }
        }