///<summary>
 /// Remove a stopwatch timer.
 ///</summary>
 ///<param name="timer"></param>
 public void Remove(StopwatchTimer timer)
 {
     _stopwatchRemoveList.Add(timer);
 }
 ///<summary>
 /// add a stopwatch timer.
 ///</summary>
 ///<param name="timer"></param>
 public void Add(StopwatchTimer timer)
 {
     _stopwatchTimerList.Add(timer);
 }