[Flutter] How to test two providers in Flutter / Riverpod?

I have 2 providers, Provider1 and Provider2, where Provider1 uses Provider2 in this way:

@riverpod
class Provider1Notifier extends _$Provider1Notifier with PersistenceHelper {

....

void buy(int id) {
final ProviderData data = getData(id);
...
}

ProviderData getData(int id) => ref.read(provider2NotifierProvider).firstWhere((g) => g.id == id);
}


In my test for Provider1, I have something like:

class MockProvider1Notifier extends Provider1Notifier {
@override
ProviderData build() {
return ProviderData(
...
);
}
}

void main() {
group('Provider1Notifier.init', ()
{
test('Do stuff...', () {
final container = createContainer(overrides: [
provider1NotifierProvider.overrideWith(() => MockProvider1Notifier()),
provider2Provider1NotifierProvider.overrideWith(() => Provider2Notifier()),
]);

Provider1Notifier notifier = container.read(provider1NotifierProvider.notifier);
notifier.doSomething(0);
...
}
}
}


When I run the test I get the error:

UnimplementedError
​

which is pointing to the line of code:

ProviderData getData(int id) => ref.read(provider2NotifierProvider).firstWhere((g) => g.id == id);


and in particular to ref.read(provider2NotifierProvider).

I do not see more error description than that. Is there anything wrong with the test setting? How to fix that?

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