public String paramString() {
		String tail = super.paramString();
		tail = tail.substring(tail.indexOf(')') + 1);
		GPoint pt = getStartPoint();
		String param = "start=(" + pt.getX() + ", " + pt.getY() + ")";
		pt = getEndPoint();
		param += ", end=(" + pt.getX() + ", " + pt.getY() + ")";
		return param + tail;
	}