* @return a Map containing the new name for each element that has to be renamed
     */
    public Map<T, String> deduplicate(Iterable<? extends T> elements) {
        return new StatefulDeduplicator(elements).getNewNames();
    }

    /*
     * This inner class hides the fact that the actual de-duplication algorithm is stateful.
     */
    private class StatefulDeduplicator {

        private final List<T> elements;