public GSM(string model, string manufacturer, decimal? price=null, Person owner=null, Battery battery=null, Display display=null)
: this(model,manufacturer)
{
this.Price = price;
this.Owner = owner;
this.Battery = battery;
this.Display = display;
}
static void Main()
{
Person pesho = new Person("Pesho");
Display display = new Display(5.4, 16000);
Battery battery = new Battery("5KR76", 6.4, 4.1, BatteryType.NiCd);
GSM gsm = new GSM("C30", "Nokia", 45.46m, pesho, battery, display);
//GSM gsm = new GSM("C30", "Nokia", owner: pesho, display: display);
Console.WriteLine(gsm.ToString());
Console.WriteLine(GSM.IPhone4S.ToString());
}