public void GivenValidUserIdGenerateInvoice()
        {
            Ride ride1 = new Ride(1, 1);
            Ride ride2 = new Ride(2, 1);
            Ride ride3 = new Ride(1, 1);

            rideRepository.AddToRideRepository("Dilip", ride1);
            rideRepository.AddToRideRepository("Dilip", ride2);
            rideRepository.AddToRideRepository("Dilip", ride3);
            Assert.AreEqual(32.0d, invoiceGenerator.returnTotalFareForMultipleRides(rideRepository.returnListByUserId("Dilip")));
            Assert.AreEqual(16.0d, invoiceGenerator.averagePerRide);
            Assert.AreEqual(2, invoiceGenerator.numberOfRides);
        }