if (!cleannodes.containsKey(key)) { cleannodes.put(key, node);
if (!cleanNodes.containsKey(key)) { cleanNodes.put(key, node);
    public void visitCleanNode(Node node) {        if (node != null) {            Key key = node.getKey();            if (!cleannodes.containsKey(key)) {                cleannodes.put(key, node);            }        }    }