Iterator<FastByIDMap.MapEntry<float[]>> Yiterator,
FastIDSet knownItemIDs,
FastIDSet userTagIDs,
IDRescorer rescorer) {
Preconditions.checkArgument(features.length > 0, "features must not be empty");
delegate = new MutableRecommendedItem();
this.features = features;
this.Yiterator = Yiterator;
this.knownItemIDs = knownItemIDs;
this.userTagIDs = userTagIDs;
this.rescorer = rescorer;