} else {
      return (bubbledTo < index) ? new MoveDesc<E>(toTrickle, elementData(index)) : null;
    }
  }

  // Returned from removeAt() to iterator.remove()
  private static final class MoveDesc<E> {
    final E toTrickle;
    final E replaced;

    MoveDesc(E toTrickle, E replaced) {
      this.toTrickle = toTrickle;
      this.replaced = replaced;
    }