class JexlNodeSet implements Set<JexlNode> {

    @Override
    public boolean contains(Object o) {
        if (o instanceof JexlNode) {
            String nodeKey = buildKey((JexlNode) o);
            return nodeMap.containsKey(nodeKey);
        }
        return false;
    }

    public  JexlNodeSet();
    public  JexlNodeSet(boolean useSourceNodeForKeys);

}