void UseSmartPhone(SmartPhone smartPhone)
{
// Cannot access private property 'Name' here
Console.WriteLine(smartPhone.Name);
// Cannot access explicit implementation of 'IMp3Player.Play'
smartPhone.Play();
// You can send the phone to the method that accepts an IMp3Player though
PlaySong(smartPhone);
// This works fine. You are sure to get the Phone name here.
Console.WriteLine(((IPhone)smartPhone).Name);
// This works fine, since the Call is public in SmartPhone.
smartPhone.Call();
}