플러터 StreamProvider 중지에 대해 질문있습니다.

버튼 클릭시 trackingOff()를 호출해서 중지시킬려고 해도 StreamProvider가 중지가 되지않아서 그러는데 StreamProvider는 중지 시킬 수 없나여?

class LocationUtil {
  late UserLocation userLocation;
  late Position _currentPosition;
  late LocationPermission checkPermission;
  StreamSubscription<Position>? positionStream;
  Geolocator geolocator = Geolocator();
  StreamController<UserLocation> _positionController =
      StreamController<UserLocation>();

  Stream<UserLocation> get locationStream => _positionController.stream;

  final LocationSettings locationSettings =
      LocationSettings(accuracy: LocationAccuracy.high);

  // 추적 버튼 클릭시에만 현재 위치 주기적으로 업데이트
  LocationUtil() {
    // 사용자의 현재 위치 계속 업데이트해주기
    positionStream =
        Geolocator.getPositionStream(locationSettings: locationSettings)
            .listen((location) {
      _positionController
          .add(UserLocation(location.latitude, location.longitude));
    });
  }

  Future<UserLocation> getCurrentLocation() async {
    try {
      final isLocationEnabled = await Geolocator.isLocationServiceEnabled();
      checkPermission = await Geolocator.checkPermission();
      log("${isLocationEnabled} isLocationEnabled 확인");
      // 권한이 없을때
      if (!isLocationEnabled) {
        log("${checkPermission} checkPermission 확인");
        // 권한 설정 확인
        if (checkPermission == LocationPermission.denied ||
            checkPermission == LocationPermission.deniedForever) {
          checkPermission = await Geolocator.requestPermission();
        }
        // 한번더 권한 취소햇으면
        if (checkPermission == LocationPermission.denied ||
            checkPermission == LocationPermission.deniedForever) {
          throw Exception("denied'");
        }
      } else if (isLocationEnabled &&
          (checkPermission == LocationPermission.always ||
              checkPermission == LocationPermission.whileInUse)) {
        _currentPosition = await Geolocator.getCurrentPosition(
            desiredAccuracy: LocationAccuracy.high);
        userLocation =
            UserLocation(_currentPosition.latitude, _currentPosition.longitude);
      }
    } catch (e) {
      log("${e} 경복궁 보여줍시다.");
      userLocation = UserLocation(37.579887, 126.976870);
    }
    log("${userLocation.latitude},${userLocation.longitude} 현재 위치 위도 경도");
    return userLocation;
  }

  void closePosition() {
    if (positionStream != null) {
      log("종료입니다");
      positionStream!.cancel();
      _positionController.close();
      positionStream = null;
    } else {}
  }

  void trackingOn(){
    positionStream!.resume();
    _positionController.onResume;


  }
  void trackingOff(){
    log("off입니다.");
     positionStream!.pause();
    _positionController.onPause;
    log("${positionStream!.isPaused}");
  }
}

 StreamProvider<UserLocation>(
          initialData: Provider.of<LocationNotifier>(context).userLocation,
          create: (context) => LocationUtil().locationStream,
          child: Consumer<LocationNotifier>(
              builder: (context, locationNotifier, _) {
            CameraPosition initialCameraPosition = CameraPosition(
                target: LatLng(Provider.of<UserLocation>(context).latitude,
                    Provider.of<UserLocation>(context).longitude),
                zoom: 18);
            log("반복하는지 테스트입니다!!!!");
            animatedViewofMap(
                lat: Provider.of<UserLocation>(context).latitude,
                lng: Provider.of<UserLocation>(context).longitude,
                zoom: null);
            return Stack(children: [
              GoogleMap(
                initialCameraPosition: initialCameraPosition,
                myLocationEnabled: true,
                mapToolbarEnabled: true,
                myLocationButtonEnabled: true,
                mapType: MapType.normal,
                onMapCreated: (GoogleMapController controller) {
                  _controller.complete(controller);
                },
                markers: markerList,
              ),
            ]);
          }),
        )