class Button : Clickable, Focusable {
    override fun click() = println("I was clicked!")
    override fun showOff() {
        super<Clickable>.showOff()
        super<Focusable>.showOff()
    }
}

fun main() {
    Button().showOff()
    Button().click()
    Button().setFocus(false)

    val b = Button()
    b.showOff()
    b.click()
    b.setFocus(false)
}