int numUsers = testData.numUsersWithPreferences(); recMetrics.forEach((name, metric) -> sysMetrics.put(name, new AverageRecommendationMetric<>(metric, numUsers)));
int numUsers = testData.numUsersWithPreferences(); recMetrics.forEach((name, metric) -> sysMetrics.put(name, new AverageRecommendationMetric<>(metric, numUsers)));