public interface Vector<E> {
	public int size();
	public boolean isEmpty();
	public E elementAtRank( int r ) throws BoundaryViolationException;
	public E replaceAtRank( int r, E e) throws BoundaryViolationException;
	public void insertAtRank( int r, E e ) throws BoundaryViolationException;
	public E removeAtRank( int r ) throws BoundaryViolationException;
}