code: public long stop() {
  	if (isRunning) {
  	    long time = _time() - start;
  	    total += time;
  	    count++;
  	    isRunning = false;
  	    return time;
  
  	}
  	return 0;
      }
docs: stops the watch
  
  @return returns the current time or 0 if watch not was running