private SlopeOneModel getModel(List<Rating> ratings) {
EventDAO dao = EventCollectionDAO.create(ratings);
UserEventDAO udao = new PrefetchingUserEventDAO(dao);
ItemDAO idao = new PrefetchingItemDAO(dao);
UserHistorySummarizer summarizer = new RatingVectorUserHistorySummarizer();
ItemItemBuildContextProvider contextFactory = new ItemItemBuildContextProvider(
udao, new DefaultUserVectorNormalizer(), summarizer);
SlopeOneModelBuilder provider = new SlopeOneModelBuilder(idao, contextFactory.get(), 0);
return provider.get();
}