public void WhatAreTheNumberOfTrips_StartingAtCAndEndingAtC_WithAMaximumOfThreeHops(string graphInput, int expectation)
        {
            //arrange
            var graph = new Graph(graphInput);

            //act
            var tripResponse = new MaxStopTripFinder(graph).FindTrip('C', 'C');

            //assert
            Assert.That(tripResponse.GetResponse(), Is.EqualTo(expectation.ToString()));
        }