@Override
    public Iterator<V> iterator() {
      refreshIfEmpty();
      return new WrappedIterator();
    }

    @Override
    public Spliterator<V> spliterator() {
      refreshIfEmpty();
      return delegate.spliterator();
    }

    /** Collection iterator for {@code WrappedCollection}. */
    class WrappedIterator implements Iterator<V> {
      final Iterator<V> delegateIterator;