SetView<Song> nonFavorites = Sets.difference(library, favorites);
SetView<Song> all = Sets.union(nonFavorites, favorites);
bus.post(new GetSongsToSyncProgressChangedEvent(this, 3, 3));
bus.post(new GetSongsToSyncFinishedEvent(this, all.size()));
return Sets.newHashSet(all);
}