googlemap flutter marker selection

import 'package:app/app.dart' as app;

class MarkerID {
  final String? markerID;
  MarkerID({this.markerID});
}

class Marker {
  final MarkerID? markerID;
  final void onTap;

  Marker({this.onTap, this.markerID});
}

class ConnectPeople extends Marker {
  final String? peopleName;
  final Function(MarkerID markerID, Marker marker)? callPeople;
  final void onTap;
  ConnectPeople({this.peopleName, this.callPeople, this.onTap}) : super();

  String? get getPeopleName => this.peopleName;
}

void main(List<String> arguments) {
  MarkerID markerID = MarkerID(markerID: "alksdlaksdja");

  ConnectPeople connectPeople = ConnectPeople(
      callPeople: (markerID, marker) {}, peopleName: "Selam Sude");

  Map<MarkerID, Marker> mapMarker = {markerID: connectPeople};

  ConnectPeople _person = mapMarker[markerID] as ConnectPeople;
  
  print(_person.getPeopleName);

  print('Hello world: ${app.calculate()}!');
}

this example, google_map package for flutter, and we are select with marker and markerID select for users and etc.