((MapChangeTracker) tracker).setTrackKeys(keys); tracker.startTracking();
((MapChangeTracker) tracker).setTrackKeys(keys); tracker.startTracking();
((MapChangeTracker) tracker).setTrackKeys(keys); tracker.startTracking();
((MapChangeTracker) tracker).setTrackKeys(keys); tracker.startTracking();
((MapChangeTracker) tracker).setTrackKeys(keys); tracker.startTracking();