public void Test()
{
gsm.AddCall(new Call(new DateTime(2016, 05, 15, 18, 30, 22), "0885 654 213", 100));
gsm.AddCall(new Call(new DateTime(2015, 11, 22, 13, 45, 23), "0888 352 351", 100));
gsm.AddCall(new Call(new DateTime(2016, 09, 19, 15, 30, 44), "0887 424 212", 100));
Console.WriteLine(gsm.CallHistoryInfo());
Console.WriteLine("Total price: {0:F2} BGN", gsm.CallPrice(0.37m));
gsm.RemoveLongestCall();
Console.WriteLine("Now the total price is {0:F2} BGN", gsm.CallPrice(0.37m));
gsm.ClearCallHistory();
Console.WriteLine(gsm.CallHistoryInfo());
}
