PickyIterable(E... elements) {
      this.elements = new ArrayList<E>(asList(elements));
    }

    @Override
    public Iterator<E> iterator() {
      return new PickyIterator();
    }

    final class PickyIterator implements Iterator<E> {
      int expectedModCount = modCount;
      int index = 0;
      boolean canRemove;

      @Override
      public boolean hasNext() {