@Test
  public void intersect() {
    MutableSet<String> set =
        MultiReaderUnifiedSet.newSetWith("1", "2", "3", "4").asReadUntouchable();
    MutableSet<String> intersect = set.intersect(UnifiedSet.newSetWith("a", "b", "c", "1"));
    Verify.assertSize(1, intersect);
    Assert.assertEquals(UnifiedSet.newSetWith("1"), intersect);

    Verify.assertEmpty(set.intersect(UnifiedSet.newSetWith("not present")));
  }