static void Main()
        {
            Battery battery = new Battery("some battery", "Nokia Battery");
            Console.WriteLine(battery.BatteryManufacturer);

            GSM gsm = new GSM("Lumia", "Nokia");
            Console.WriteLine(gsm.Manufacturer);
        }
        static void Main()
        {
            Battery battery = new Battery("some battery", "Nokia Battery");

            Console.WriteLine(battery.BatteryManufacturer);

            GSM gsm = new GSM("Lumia", "Nokia");

            Console.WriteLine(gsm.Manufacturer);
        }