private void OnScaleChanged()
 {
     //Update Layer Visibilities is expensive, so wait for the map to stop navigating so
     //map navigation performance doesn't suffer from it.
     if (_updateTimer == null)
     {
         _updateTimer = new ThrottleTimer(100)
         {
             Action = UpdateLayerVisibilities
         };
     }
     _updateTimer.Invoke();
 }
 private void UpdateAttributionItems()
 {
     // wait for the map to stop navigating so
     //map navigation performance doesn't suffer from it.
     if (_updateItemsTimer == null)
     {
         _updateItemsTimer = new ThrottleTimer(100)
         {
             Action = UpdateAttributionItemsImpl
         };
     }
     _updateItemsTimer.Invoke();
 }