if (ChainBuilderAgent.DEBUG) System.err.println("setting point # "+index+", # of points is "+points.size());
	public void setPoint(int index,Point2D pt) {		if (ChainBuilderAgent.DEBUG)		System.err.println("setting point # "+index+", # of points is "+points.size());		if (points.size() <= index) {			points.add(index,pt);		}		else			points.set(index,pt);		updateBounds();	}