added comments and refactored code

lib/pages/map_page.dart

@@ -20,7 +20,7 @@ class MapPage extends StatefulWidget {
 }
 
 class _MapPageState extends State<MapPage> {
-  final mapController = MapController();
+  final _mapController = MapController();
   late FloodStationProvider _floodStationProvider;
 
   @override
@@ -35,7 +35,7 @@ class _MapPageState extends State<MapPage> {
       );
     }
     return FlutterMap(
-      mapController: mapController,
+      mapController: _mapController,
       options: MapOptions(
         cameraConstraint: CameraConstraint.containCenter(
             bounds: LatLngBounds.fromPoints(_floodStationProvider.allStations
@@ -47,7 +47,7 @@ class _MapPageState extends State<MapPage> {
         initialZoom: 6,
       ),
       children: [
-        openStreetMapTileLayer,
+        _openStreetMapTileLayer,
         MarkerClusterLayerWidget(
           options: MarkerClusterLayerOptions(
               maxClusterRadius: 45,
@@ -56,13 +56,14 @@ class _MapPageState extends State<MapPage> {
               padding: EdgeInsets.all(50),
               maxZoom: 15,
               markers: _stationsAsMarkers(_floodStationProvider.allStations),
-              builder: _markerBuilder),
+              builder: _clusterMarkerBuilder),
         )
       ],
     );
   }
 
-  Widget _markerBuilder(BuildContext context, List<Marker> markers) {
+  // builds the clustered marker
+  Widget _clusterMarkerBuilder(BuildContext context, List<Marker> markers) {
     return Container(
       decoration: BoxDecoration(
         borderRadius: BorderRadius.circular(20),
@@ -71,12 +72,13 @@ class _MapPageState extends State<MapPage> {
       child: Center(
         child: Text(
           markers.length.toString(),
-          style: const TextStyle(color: Colors.white),
+          style: TextStyle(color: Theme.of(context).colorScheme.onTertiary),
         ),
       ),
     );
   }
 
+  // gets a list of markers from the list of all stations
   List<Marker> _stationsAsMarkers(List<FloodStation> stations) {
     return stations
         .map<Marker>(
@@ -91,7 +93,7 @@ class _MapPageState extends State<MapPage> {
         .toList();
   }
 
-  _markerTapped(FloodStation station) {
+  void _markerTapped(FloodStation station) {
     showDialog(
       context: context,
       builder: (context) => MapPopup(
@@ -104,7 +106,7 @@ class _MapPageState extends State<MapPage> {
   }
 }
 
-TileLayer get openStreetMapTileLayer => TileLayer(
+TileLayer get _openStreetMapTileLayer => TileLayer(
       urlTemplate: 'https://tile.openstreetmap.org/{z}/{x}/{y}.png',
       userAgentPackageName: 'dev.fleaflet.flutter_map.example',
       tileProvider: CancellableNetworkTileProvider(),