String message = "Timed out";
          // This try-finally block ensures that we complete the timeout future, even if attempting
          // to produce the message throws (probably StackOverflowError from delegate.toString())
          try {
            if (timer != null) {
              long overDelayMs = Math.abs(timer.getDelay(MILLISECONDS));

      prev.setFuture(curr);
      prev = curr;
    }
    // prev represents the 'innermost' future
    prev.set("done");
    assertTrue(orig.isDone());
  }

  // Verify that StackOverflowError in a long chain of SetFuture doesn't cause the entire toString
  // call to fail
  @J2ktIncompatible
  @GwtIncompatible
  @AndroidIncompatible // b/391667564: crashes from stack overflows

    return outputFuture;
  }

  enum RunningState {
    NOT_RUN,
    CANCELLED,
    STARTED,
  }

  /**
   * This class helps avoid a StackOverflowError when large numbers of tasks are submitted with
   * {@link MoreExecutors#directExecutor}. Normally, when the first future completes, all the other

    return outputFuture;
  }

  enum RunningState {
    NOT_RUN,
    CANCELLED,
    STARTED,
  }

  /**
   * This class helps avoid a StackOverflowError when large numbers of tasks are submitted with
   * {@link MoreExecutors#directExecutor}. Normally, when the first future completes, all the other

           *
           * Also, it's nice that this approach should let us catch *only* ClassNotFoundException
           * instead of having to catch more broadly (potentially even including, say, a
           * StackOverflowError).
           */
          Class.forName("java.lang.invoke.VarHandle");
        } catch (ClassNotFoundException beforeJava9) {
          return null;
        }
        return new VarHandleAtomicHelper();