class MetricsUtils {

  public static void addLatency(Map<String, List<Double>> stats, String id, double lat) {
    List<Double> latList = stats.get(id);
    if (null == latList) {
      latList = new LinkedList<Double>();
      stats.put(id, latList);
    }
    latList.add(lat);
  }

  private  MetricsUtils();

}