@Test
public void testIterator() {

  FastIDSet set = buildTestFastSet();
  Collection<Long> expected = Sets.newHashSetWithExpectedSize(3);
  expected.add(1L);
  expected.add(2L);
  expected.add(3L);
  LongPrimitiveIterator it = set.iterator();
  while (it.hasNext()) {
    expected.remove(it.nextLong());
  }
  assertTrue(expected.isEmpty());
}