fun f(x: Any): String {
  when {
    x is A<*> -> return x /*as A<*> */.call(block = local fun <anonymous>(y: Any?): @FlexibleNullability String? {
      return "OK"
    }
 /*-> @FlexibleNullability I<@FlexibleNullability Any?>? */) /*!! String */
  }
  return "Fail"
}

