FILE: box.kt
    private open class C : R|B| {
        public constructor(): R|C| {
            super<R|B|>()
        }

        public open override fun foo(d: R|kotlin/Any?|): R|kotlin/String| {
            ^foo String(C)
        }

    }
    public final fun box(): R|kotlin/String| {
        ^box R|/D.D|().R|/B.foo|(String(s))
    }
