public Iterator<T> getBookmark() {
    LinkedSetIterator toRet = new LinkedSetIterator();
    toRet.next = this.bookmark.next;
    this.bookmark = toRet;
    return toRet;
  }
@Test(timeout=60000)
  public void testBookmarkSetToHeadOnAddToEmpty() {
    LOG.info("Test bookmark is set after adding to previously empty set.");
    Iterator<Integer> it = set.getBookmark();
    assertFalse(it.hasNext());
    set.add(list.get(0));
    set.add(list.get(1));

    it = set.getBookmark();
    assertTrue(it.hasNext());
    assertEquals(it.next(), list.get(0));
    assertEquals(it.next(), list.get(1));
    assertFalse(it.hasNext());
  }