Recommender recommender2,
int samples,
RunningAverage tracker,
String tag) throws TasteException {
printHeader();
LongPrimitiveIterator users = recommender1.getDataModel().getUserIDs();
while (users.hasNext()) {
long userID = users.nextLong();
List<RecommendedItem> recs1 = recommender1.recommend(userID, samples);
List<RecommendedItem> recs2 = recommender2.recommend(userID, samples);
FastIDSet commonSet = new FastIDSet();
long maxItemID = setBits(commonSet, recs1, samples);
FastIDSet otherSet = new FastIDSet();