How to add an object to flutter_realm? - flutter

Question

The following Exception is thrown when I try to add an object
Maybe I misunderstand how functions work.
I couldn't find something helpful in documentation too
Unhandled Exception: Unhandled error PlatformException(-1, Attempting to create an object of type 'Country' with an existing primary key value ''., {
RLMRealmCoreVersion = "";
RLMRealmVersion = "3.17.3";
}, null) occurred in Instance of 'CountriesBloc'.
Here is my code . I have an CountriesToRealm event and I want to save my objects in flutter_realm when I add the event . I add it when I load countries by http request
if (event is CountriesToRealm) {
for (int i = 0; i < event.countries.length; ++i) {
Country country = event.countries[i];
print(country.name);
if (country.name == null || country.name.isEmpty) {}
final query = Query('Country').equalTo('name', country.name);
final List all = await realm.objects(query);
if (all.isEmpty) {
await realm.createObject('Country', country.toMap(withId: true));
}
}
final List allcountries = await event.realm.allObjects('Country');
if (allcountries.length == event.countries.length) {
yield CountriesAddedToRealmState();
} else {
yield FailedToAddCountriesState();
}
}
Also Realm Provider
import 'package:flutter/material.dart';
import 'package:flutter_realm/flutter_realm.dart';
import 'package:uuid/uuid.dart';
class RealmProvider extends StatefulWidget {
final Widget Function(Realm) builder;
const RealmProvider({this.builder}) : super();
#override
_RealmProviderState createState() => _RealmProviderState();
}
class _RealmProviderState extends State<RealmProvider> {
Future<Realm> realm;
#override
void initState() {
super.initState();
final configuration = Configuration(inMemoryIdentifier: Uuid().v4());
realm = Realm.open(configuration);
}
#override
Widget build(BuildContext context) {
return FutureBuilder<Realm>(
future: realm,
builder: (context, snapshot) {
if (snapshot.data == null) {
return Scaffold(
appBar: AppBar(),
body: Center(
child: CircularProgressIndicator(),
),
);
}
return widget.builder(snapshot.data);
},
);
}
}
Thank you for your help