public int compareTo(Point point){
		if (point == null) return 1;
		if (this.equals(point)) return 0;
		if (getX() > point.getX()) return 1;
		if (getY() > point.getY()) return 1;
		if (getZ() > point.getZ()) return 1;
		if (getX() < point.getX()) return -1;
		if (getY() < point.getY()) return -1;
		if (getZ() < point.getZ()) return -1;
		return 0;
	}