}

  @J2ktIncompatible
  @GwtIncompatible // used only in GwtIncompatible tests
  private static Predicate<StackTraceElement> hasClassName(Class<?> clazz) {
    return element -> element.getClassName().equals(clazz.getName());
  }

  private static final class CallerClass1 {
    static ListenableFuture<String> makeImmediateCancelledFuture() {
      return immediateCancelledFuture();
    }