Can someone help me finish the following piece of Java code?

package alg.np;

import java.util.List; import java.util.Set;

import alg.Recommender; import profile.Profile; import util.reader.DatasetReader;

import org.apache.commons.math3.distribution.NormalDistribution;

public class PopularityRecommender extends Recommender { // threshold above which a rating is considered to be an upvote private Double ratingThreshold; // significance level for Wilson score private Double significanceLevel; // a profile of scores used to sort the items for recommendation private Profile scores;

/** * constructor - creates a new PopularityRecommender object * @param reader - dataset reader * @param ratingThreshold * @param significanceLevel */ public PopularityRecommender(final DatasetReader reader, double ratingThreshold, double significanceLevel) { super(reader); this.ratingThreshold = ratingThreshold; this.significanceLevel = significanceLevel; setScores(); } /** * constructor - creates a new PopularityRecommender object * @param reader - dataset reader * @param ratingThreshold * */ public PopularityRecommender(final DatasetReader reader, double ratingThreshold) { super(reader); this.ratingThreshold = ratingThreshold; this.significanceLevel = 1.0; setScores(); } public void setSignificanceLevel(double level) { // scores are recomputed whenever the significance level is // changed this.significanceLevel = level; setScores(); } public void setRatingThreshold(double threshold) { // scores are recomputed whenever the rating threshold is // changed this.ratingThreshold = threshold; setScores(); } private void setScores() { scores = new Profile(0); // Get all the items in the dataset Set itemIds = reader.getItems().keySet(); // Set the score of each item and add it into scores // COMPLETE THIS FUNCTION TO INSTEAD CALCULATE THE SCORE // AS PHAT - the proportion of up-votes // obtained by each item. // Count every time an item has // appeared in a user profile. This is its total number of // votes. // Count every time the item has received a rating greater than // or equal to the ratingThreshold - this is its number of up-votes // phat is the ratio of up-votes to total number of votes // apply the Wilson formula to correct phat, taking into account // the total number of votes for (Integer item : itemIds) { scores.addValue(item, 0.0); } } public Profile getRecommendationScores(Integer userId) { return scores; }

/** * @returns the recommendations based on the target item * @param itemId - the target item ID */ public List getRecommendations(Integer userId) { Profile userProfile = reader.getUserProfiles().get(userId); return getRecommendationsFromScores(userProfile,scores); } }