if (localState != null) {
        // Don't print the actual array! We don't want inCompletionOrder(list).toString() to have
        // quadratic output.
        return "inputCount=["
            + localState.inputFutures.length
            + "], remaining=["
            + localState.incompleteOutputCount.get()
            + "]";
      }
      return null;
    }
  }