public void ShouldCountCitiesStartsWithLetter() { CityListManager listManager = new CityListManager(); var city1 = new City("Karpacz"); var city2 = new City("Wieleń"); var city3 = new City("Warszawa"); listManager.AddElement(city1); listManager.AddElement(city2); listManager.AddElement(city3); var result = listManager.CountElementsStartWithLetter("W"); Assert.AreEqual(result, 2); }