public MobilePhone(string model, string mnufctr, int price, string owner, BatteryFeatures battery, ScreenFeatures screen)
 {
     this.model        = model;
     this.manufacturer = mnufctr;
     this.price        = price;
     this.owner        = owner;
     battery           = new BatteryFeatures(battery.model, battery.idleTime, battery.hoursTalk);
     this.battery      = battery;
     screen            = new ScreenFeatures(screen.size, screen.color);
     this.screen       = screen;
 }
 public MobilePhone(string model, string mnufctr, int price, string owner, BatteryFeatures battery)
     : this(model, mnufctr, price, owner, new BatteryFeatures(), new ScreenFeatures())
 {
 }