class CategoryGraph implements WikiConstants, Serializable {

    public double getDepth() throws WikiApiException {
        if (depth < 0) {    // has not been initialized
            if (rootPathMap != null) {
                this.depth = getDepthFromRootPathMap();
                logger.info("Getting depth from RootPathMap: " + this.depth);

            }
            else {
                depth = computeDepth();
                logger.info("Computing depth of the hierarchy: " + this.depth);
            }
        }
        return depth;
    }

    public  CategoryGraph();
    public  CategoryGraph(Wikipedia pWiki, File location);
    public  CategoryGraph(Wikipedia pWiki);
    public  CategoryGraph(Wikipedia pWiki, List<String> filterList);
    public  CategoryGraph(Wikipedia pWiki, Iterable<Category> categories);
    public  CategoryGraph(Wikipedia pWiki, Iterable<Category> categories, List<String> filterList);
    protected  CategoryGraph(Wikipedia pWiki, Set<Integer> pPageIDs);
    public  CategoryGraph(Wikipedia pWiki, DirectedGraph<Integer,DefaultEdge> pGraph);

}