public void GivenAListOfTalks_WhenCreatingTheMorningSession_ThenCreateASessionFor180Minutes() { var listOfTalks = getListOfTalks(); var factory = new SessionFactory(); var morningSession = factory.CreateMorningSession(listOfTalks); Assert.That(morningSession.Sum(x => x.Duration), Is.LessThanOrEqualTo(180)); }