@Override
    public Map<Class<?>, Set<EventHandler>> findAllSubscribers(Object listener) {
      Map<Class<?>, Set<EventHandler>> found = HandlerFinder.ANNOTATED.findAllSubscribers(listener);
      Map<Class<?>, Set<EventHandler>> sorted = new HashMap<Class<?>, Set<EventHandler>>();
      for (Map.Entry<Class<?>, Set<EventHandler>> entry : found.entrySet()) {
        SortedSet<EventHandler> handlers = new TreeSet<EventHandler>(handlerComparator);
        handlers.addAll(entry.getValue());
        sorted.put(entry.getKey(), handlers);
      }
      return sorted;
    }
Delegates to {@code HandlerFinder.ANNOTATED}, then sorts results by {@code EventHandler#toString}
otto/src/test/java/com/squareup/otto/UnregisteringHandlerTest.java