* UnIterableQueue.iterator().
     */
    assertEquals(5, consumingIterator.next().intValue());
  }

  private static class UnIterableQueue<T> extends ForwardingQueue<T> {
    private final Queue<T> queue;

    UnIterableQueue(Queue<T> queue) {
      this.queue = queue;
    }

    @Override
    public Iterator<T> iterator() {