/// <summary>Evaluate an iterative recommender on the folds of a dataset split, display results on STDOUT</summary>
/// <param name="recommender">an item recommender</param>
/// <param name="num_folds">the number of folds</param>
/// <param name="test_users">a collection of integers with all test users</param>
/// <param name="candidate_items">a collection of integers with all candidate items</param>
/// <param name="candidate_item_mode">the mode used to determine the candidate items</param>
/// <param name="repeated_events">allow repeated events in the evaluation (i.e. items accessed by a user before may be in the recommended list)</param>
/// <param name="max_iter">the maximum number of iterations</param>
/// <param name="find_iter">the report interval</param>
/// <param name="show_fold_results">if set to true to print per-fold results to STDERR</param>
static public void DoRatingBasedRankingIterativeCrossValidation(
this RatingPredictor recommender,
uint num_folds,
IList <int> test_users,
IList <int> candidate_items,
CandidateItems candidate_item_mode,
RepeatedEvents repeated_events,
uint max_iter,
uint find_iter = 1,
bool show_fold_results = false)
{
var split = new RatingCrossValidationSplit(recommender.Ratings, num_folds);
recommender.DoRatingBasedRankingIterativeCrossValidation(split, test_users, candidate_items, candidate_item_mode, repeated_events, max_iter, find_iter);
}