String className,
DetectorFactory factory,
	private DetectorNode addOrCreateDetectorNode(			String className,			Map<String, DetectorNode> nodeMap,			Map<String, DetectorFactory> factoryMap,			ConstraintGraph constraintGraph)		throws OrderingConstraintException {		DetectorNode node = nodeMap.get(className);		if (node == null) {			DetectorFactory factory = factoryMap.get(className);			if (factory == null)				throw new OrderingConstraintException("Unknown detector in ordering constraint: " + className);			node = new DetectorNode(factory);			nodeMap.put(className, node);			constraintGraph.addVertex(node);		}		return node;	}