// IGNORE_BACKEND_FIR: JVM_IR
// TARGET_BACKEND: JVM
// WITH_REFLECT

import kotlin.reflect.jvm.reflect

inline class C(val x: Int)

fun C.f(x: (String) -> Unit = { OK: String -> }) = x.reflect()?.parameters?.singleOrNull()?.name

fun box(): String = C(0).f() ?: "null"