* fetch the extra elements, it throws an unchecked exception.
   */
  static class ThrowsAtEndIterator<E> implements Iterator<E> {
    Iterator<E> iterator;

    public ThrowsAtEndIterator(Iterable<E> iterable) {
      this.iterator = iterable.iterator();
    }

    @Override
    public boolean hasNext() {

   * fetch the extra elements, it throws an unchecked exception.
   */
  static class ThrowsAtEndIterator<E> implements Iterator<E> {
    Iterator<E> iterator;

    public ThrowsAtEndIterator(Iterable<E> iterable) {
      this.iterator = iterable.iterator();
    }

    @Override
    public boolean hasNext() {