Interface

#control(
    layout(x: 'i32, y: 'i32)'void
)

#button(
    click()'void
)

button #button #control (
    click() {
        console.writeLine("clicked")
        void
    }

    layout(x : 'i32, y : 'i32) { void } 
) { this }

b : button()
ib : b as #button
ib.click()

ic : ib as #control? 
// when casting from between interfaces you will receive
// an option because the underlying class may not implement this interface
ic?.layout(0, 0)