@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());
}