public void UnregisterSweepModeObserver(ISweepModeObserver ob) { if (ob != null && _sweepModeObs.Contains(ob)) { _sweepModeObs.Remove(ob); } }
public void RegisterSweepModeObserver(ISweepModeObserver ob) { if (ob != null && !_sweepModeObs.Contains(ob)) { _sweepModeObs.Add(ob); } }