List<T> list = asList(elements);
    return new Iterable<T>() {
      @Override
      public Iterator<T> iterator() {
        return list.iterator();
      }
    };
  }

  public void test_contains_null_set_yes() {
    Iterable<@Nullable String> set = newHashSet("a", null, "b");
    assertTrue(Iterables.contains(set, null));
  }

  public void test_contains_null_set_no() {