private void UnregisterMarkerProvider(IMarkerProvider markerProvider)
 {
     markerProvider.MarkersRemoved -= MarkerProvider_MarkersRemoved;
     markerProvider.NewMarkers -= MarkerProvider_NewMarkers;
     markerProvider.RetrieveMarkersFailed -= MarkerProvider_RetrieveMarkersFailed;
     markerProvider.LogReady -= Plugin_LogReady;
     markerProvider.PluginLoadFailed -= Plugin_PluginLoadFailed;
     markerProvider.PluginLoaded -= MarkerProvider_PluginLoaded;
     markerProvider.StopRetrievingMarkers();
     markerProvider.Unload();
 }