}

  @Override
  @CheckForNull
  protected String pendingToString() {
    @RetainedLocalRef ListenableFuture<? extends V> localInputFuture = inputFuture;
    @RetainedLocalRef Class<X> localExceptionType = exceptionType;
    @RetainedLocalRef F localFallback = fallback;
    String superString = super.pendingToString();
    String resultString = "";
    if (localInputFuture != null) {

      setStackTrace(new StackTraceElement[0]);
      return this; // no stack trace, wouldn't be useful anyway
    }
  }

  @Override
  @CheckForNull
  protected String pendingToString() {
    @RetainedLocalRef ListenableFuture<? extends V> localInputFuture = delegateRef;
    @RetainedLocalRef ScheduledFuture<?> localTimer = timer;
    if (localInputFuture != null) {