static void Main()
{
Display someDisplay = new Display("4.5inch", "165Million");
Battery someBattery = new Battery("Varta", 10.00, 10.00);
GSM myPhone = new GSM("G3", "JIAYU", "Pencho", 390.00m, someBattery, someDisplay);
myPhone.AddCallToHist(DateTime.Now, "088617555", 180);
myPhone.AddCallToHist(DateTime.Now, "099953312", 2000);
myPhone.AddCallToHist(DateTime.Now, "125989364", 369);
myPhone.AddCallToHist(DateTime.Now, "058933153", 600);
myPhone.DisplayCallHistory();
Console.WriteLine("Price for all calls");
//calculating totalPrice for all calls
decimal pricePerMinute = 0.37m;
decimal totalPrice = 0m;
totalPrice=myPhone.TotalPriceCall(pricePerMinute);
Console.WriteLine(totalPrice);
//Remove LongestCall and calculating price again
myPhone.RemoveLongestCall();
Console.WriteLine("Price for all calls after removing the longest call");
totalPrice = myPhone.TotalPriceCall(pricePerMinute);
Console.WriteLine(totalPrice);
myPhone.DisplayCallHistory();
myPhone.ClearCallHistory();
Console.WriteLine("This is cleared call history:");
myPhone.DisplayCallHistory();
}