public static void TestFunctionality() { GSM nokia1102 = new GSM("Nokia 5210", "Nokia", 29, "Mtel", new Battery(BatteryModel.NiCd550), new Display(2, "2")); nokia1102.AddCallToHistory(new Call(DateTime.Now, "mom", 90)); nokia1102.AddCallToHistory(new Call(DateTime.Now, "mom", 99)); nokia1102.AddCallToHistory(new Call(DateTime.Today, "mom", 7)); nokia1102.AddCallToHistory(new Call(DateTime.Today, "mom", 40)); nokia1102.PrintCallHistory(); Console.WriteLine(nokia1102.CurrentBill(0.37M)); int longestCall = int.MinValue; int longestCallIndex = new int(); for (int i = 0; i < nokia1102.CallHistory.Count; i++) { if (nokia1102.CallHistory[i].CallDuratiin > longestCall) { longestCall = nokia1102.CallHistory[i].CallDuratiin; longestCallIndex = i; } } nokia1102.DeleteCallAtPositionFromHistory(longestCallIndex); Console.WriteLine(nokia1102.CurrentBill(0.37M)); nokia1102.ClearCallHistory(); nokia1102.PrintCallHistory(); }