assertFalse(set.containsAll(Sets.newTreeSet(asList("f", "d", "a"))));
  }

  @SuppressWarnings("CollectionIncompatibleType") // testing incompatible types
  public void testContainsAll_sameComparator_stringVsInt() {
    SortedSet<String> set = of("a", "b", "f");
    SortedSet<Integer> unexpected = Sets.newTreeSet(Ordering.natural());
    unexpected.addAll(asList(1, 2, 3));