public static void convertRoot(Configuration configuration, RootDoc rd, String outputdir) {
        if (rd == null || outputdir == null) {
            return;
        }
        PackageDoc[] pds = rd.specifiedPackages();
        for (int i = 0; i < pds.length; i++) {
            convertPackage(configuration, pds[i], outputdir);
        }
        ClassDoc[] cds = rd.specifiedClasses();
        for (int i = 0; i < cds.length; i++) {
            convertClass(configuration, cds[i],
                getPackageOutputDir(outputdir, cds[i].containingPackage()));
        }
    }