我使用的是riverpod_generator和riverpod中的AsyncNotifier

part 'auth_controller.g.dart';

// 3. annotate
@riverpod
// 4. extend like this
class AuthController extends _$AuthController {
  // 5. override the [build] method to return a [FutureOr]
  @override
  FutureOr<void> build() {
    // 6. return a value (or do nothing if the return type is void)
  }

  Future<void> signIn({
    required String email,
    required String password,
  }) async {
    final authRepository = ref.read(authRepositoryProvider);
    state = const AsyncLoading();
    state = await AsyncValue.guard(
        () async => await authRepository.signIn(email, password));
  }

  Future<void> logout() async {
    state = const AsyncLoading();
    state = await AsyncValue.guard(() async {
      await FirebaseAuth.instance.signOut();
    });
  }
}

因此，当我试图注销时，错误将发生，它说
未来已完成
如何解决这个问题？