private void AddFenceMonitoring( ICallback callback, GeoFence[] geoFences )
{
if( geoFences.Length == 0 )
return;
if( geoFences.Length == 1 )
GeoFenceMonitoring.Instance.AddGeoFence( geoFences[ 0 ], callback );
else
GeoFenceMonitoring.Instance.AddGeoFences( new HashSet<GeoFence>( geoFences ), callback );
if( !LocationTracker.Instance.ContainsListener( GeoFenceMonitoring.NAME ) )
LocationTracker.Instance.AddListener( GeoFenceMonitoring.NAME, GeoFenceMonitoring.Instance );
}