public static void generate(ConfigurationImpl configuration,
                                ClassTree classtree) {
        TreeWriter treegen;
        String filename = "overview-tree.html";
        try {
            treegen = new TreeWriter(configuration, filename, classtree);
            treegen.generateTreeFile();
            treegen.close();
        } catch (IOException exc) {
            configuration.standardmessage.error(
                        "doclet.exception_encountered",
                        exc.toString(), filename);
            throw new DocletAbortException();
        }
    }