static unsafe void OnAsyncConversionComplete(ARWorldMapRequestStatus status, int worldMapId, IntPtr context)
        {
            var handle     = GCHandle.FromIntPtr(context);
            var onComplete = (Action <ARWorldMapRequestStatus, ARWorldMap>)handle.Target;

            if (status.IsError())
            {
                onComplete(status, default(ARWorldMap));
            }
            else
            {
                var worldMap = new ARWorldMap(worldMapId);
                onComplete(status, worldMap);
            }

            handle.Free();
        }