code: public Timer newTimer(String opType, int sampleCount)
      {
          final Timer timer = new Timer(sampleCount);
  
          if (!timers.containsKey(opType))
              timers.put(opType, new ArrayList<Timer>());
  
          timers.get(opType).add(timer);
          return timer;
      }
docs: build a new timer and add it to the set of running timers.