public MobilePhone(string model, string manufacturer, string owner, decimal price, Battery battery, Display display)
     : this(model, manufacturer, owner, price)
 {
     this.Battery = battery;
     this.Display = display;
 }
 public MobilePhone(string model, string manufacturer, Battery battery, Display display)
     : this(model, manufacturer)
 {
     this.Battery = battery;
     this.Display = display;
 }