public static void exportDocuments(DocumentmanagerConfig.Builder documentManagerCfg, String toDirectory) throws IOException {
        exportCfg(new DocumentmanagerConfig(documentManagerCfg), toDirectory + "/" + "documentmanager.cfg");
    }
Exports a complete set of configuration-server format config files.

@param toDirectory  the directory to export to, current dir if null
@throws IOException if exporting fails, some files may still be created
config-model/src/main/java/com/yahoo/schema/derived/DerivedConfiguration.java