}

    @Override
    public Iterator<Set<E>> iterator() {
      return new AbstractIndexedListIterator<Set<E>>(size()) {
        @Override
        protected Set<E> get(final int setBits) {
          return new SubSet<>(inputSet, setBits);
        }
      };
    }

    @Override
    public boolean contains(@CheckForNull Object obj) {
      if (obj instanceof Set) {
        Set<?> set = (Set<?>) obj;