public GSM(string manifacturer, string model, int price, string owner, Battery battery, Display display)
: this(manifacturer, model)
{
this.Price = price;
this.Owner = owner;
this.Battery = battery;
this.Display = display;
}
public GSM(string model, string manufacturer, double price, string owner,Battery battery, Display display,List<Call> calls)
{
this.Model = model;
this.Manufacturer = manufacturer;
this.Price = price;
this.Owner = owner;
this.Display = display;
this.Battery = battery;
this.CallHistory = new List<Call>();
}