class GenericIndexer implements Indexer {

    @Override
    public void checkId(Index.Key key) throws IOException {
        if (WorkspaceFamily.UTIL_CAL.equals(key.getFamily())) {
            if (!key.getId().equals("Calendars")) {
                throw new IOException("Only one calendar file is allowed");
            }
        }
    }

      GenericIndexer(Path file, Path rootFolder);

}