public boolean equals(Object object){
		if(!(object instanceof ShapeEdge)) return false;
		ShapeEdge edge = (ShapeEdge) object;
		if(startPoint.equals(edge.getStartPoint())
			&& endPoint.equals(edge.getEndPoint())) return true;
		if(startPoint.equals(edge.getEndPoint())
			&& endPoint.equals(edge.getStartPoint())) return true;
		return false;
	}