public static void CallHistoryTest() { Console.WriteLine("*************Call History Test*************"); //Create an instance of the GSM class. GSM samsung = new GSM("S5", "Samsung", 1000, "Ivancho", new Battery("G2", 50, 5, BatteryType.LiIon), new Display(5, 500000)); //Add few calls. samsung.AddCall(new Call("30/05/2016", "14:06", "0884089756", 104)); samsung.AddCall(new Call("23/01/2015", "12:42", "0883208975", 311)); samsung.AddCall(new Call("31/04/2016", "11:12", "0884589752", 151)); //Display the information about the calls. for (int i = 0; i < samsung.CallHistory.Count; i++) { Console.WriteLine(samsung.CallHistory[i]); } //Assuming that the price per minute is 0.37 calculate and print the total price of the calls in the history. Console.WriteLine("Calls Price: {0:f2}", samsung.GetTotalCallPrice(0.37m)); //Remove the longest call from the history and calculate the total price again. Call longestCall = samsung.CallHistory[0]; foreach (var call in samsung.CallHistory) { if (call.Duration > longestCall.Duration) { longestCall = call; } } samsung.DeleteCall(longestCall); Console.WriteLine("Calls Price without longest: {0:f2}", samsung.GetTotalCallPrice(0.37m)); //Finally clear the call history and print it. samsung.ClearCallHistory(); Console.WriteLine("Call history cleared!"); }