private String createId(ArrayList<Rod> currentRodList, ArrayList<Rod> possibilitiesLeft) {
		StringBuilder id = new StringBuilder();
		for(Rod rod : currentRodList) {
			id.append(rod.getIndex());
		}
		id.append(":");
		for(Rod rod : possibilitiesLeft) {
			id.append(rod.getIndex());
		}
		return id.toString();
	}