ItemSimilarity similarity,
CandidateItemsStrategy candidateItemsStrategy) {
super(dataModel, candidateItemsStrategy);
Preconditions.checkArgument(similarity != null, "similarity is null");
this.similarity = similarity;
this.refreshHelper = new RefreshHelper(null);
refreshHelper.addDependency(dataModel);
refreshHelper.addDependency(similarity);
capper = buildCapper();
}