protected void navLinkTree() {
        navCellStart();
        PackageDoc[] packages = configuration.root.specifiedPackages();
        if (packages.length == 1 && configuration.root.specifiedClasses().length == 0) {
            printHyperLink(pathString(packages[0], "package-tree.html"), "",
                           configuration.getText("doclet.Tree"), true, "NavBarFont1");
        } else {
            printHyperLink(relativePath + "overview-tree.html", "",
                           configuration.getText("doclet.Tree"), true, "NavBarFont1");
        }
        navCellEnd();
    }