title: save LatLng(geopoint) value in firestore document / geolocator package
body: <p>i am new to flutter and  i need to save a value inside my user document. 
  i can print the values but i do not know how to assign the values of LatLan to a variable and get them saved in firestore. 
  here is my searchMapPlaceWidget that returns them values</p>
  
  <pre class="lang-dart prettyprint-override"><code> SearchMapPlaceWidget(
     darkMode: true,
     placeType: PlaceType.establishment,
     language: 'se',
     apiKey: kGoogleApiKey,
     onSelected: (place) async {
       final geolocation =
         await place.geolocation;
  
       final chosenPlace = Marker(
         markerId: MarkerId(
           'chosen-location'),
         icon: BitmapDescriptor
         .defaultMarker,
         position:
         geolocation.coordinates);
       GoogleMapController controller =
         await _mapController.future;
       setState(() {
         _markers.add(chosenPlace);
       });
       print(chosenPlace.position);
  
       controller.animateCamera(
         CameraUpdate.newLatLng(
           geolocation.coordinates));
       controller.animateCamera(
         CameraUpdate.newLatLngBounds(
           geolocation.bounds, 50));
     },
  
   ),
  </code></pre>
  
  <p>here is the function that i wrote which is not working </p>
  
  <pre><code>static void addGeoPoint(User user)async{
  var pos = await location.getLocation();
  GeoFirePoint point = geo.point(latitude: pos.latitude, longitude: pos.longitude);
  return usersRef.document(user.id).updateData({
    'myAddress' : point.data
  });
  </code></pre>
  
  <p>}</p>
  
  <p>how do i save the position values of 'chosenPlace' ? </p>
  
  <p>thank you all</p>