FILE: main.kt
    public final operator fun R|Base|.plus(s: R|kotlin/String|): R|kotlin/Int| {
        ^plus Int(0)
    }
    public final class Derived : R|Base| {
        public constructor(): R|Derived| {
            super<R|Base|>()
        }

        public final fun test_1(x: R|Base|): R|kotlin/Unit| {
            lval y: R|kotlin/Int| = R|<local>/x|.R|/plus|(String())
            R|<local>/y|.R|kotlin/Int.inc|()
        }

        public final fun test_2(x: R|Base|): R|kotlin/Unit| {
            lval y: R|kotlin/String!| = R|<local>/x|.R|/Base.plus|(vararg(String()))
            R|<local>/y|.R|kotlin/String.length|
        }

    }
