// This type represents a blue window closer. It takes, however, a generic window type, // so it is capable of closing any type of window, not just a blue window. This is because // the program will pass it a generic window; the program doesn't know there is a more // specific type. func (bwc *BlueWindowCloser) CloseWindow(w af.Window) string { w.Close() return "You closed a window with a blue window closer" }
func (gwc *GreenWindowCloser) CloseWindow(w af.Window) string { w.Close() return "You closed a window with a green window closer" }