Erro ao mudar da tela FormContact para ContactList

Está tudo igual conforme é passado no curso

void main() {
  testWidgets('Salvar Contato', (tester) async {
    final mockContatoDao = MockContatoDao();
    await tester.pumpWidget(Banco(
      contatoDao: mockContatoDao,
    ));

    final dashboard = find.byType(Dashboard);
    expect(dashboard, findsOneWidget);

    final transferenciaFeatureItem = find.byWidgetPredicate((widget) =>
        fetureItemMatcher(widget, 'Transferencia', Icons.monetization_on));
    expect(transferenciaFeatureItem, findsOneWidget);
    await tester.tap(transferenciaFeatureItem);
    await tester.pumpAndSettle();

    final listaContato = find.byType(ListaContato);
    expect(listaContato, findsOneWidget);

    final fabNovoContato = find.widgetWithIcon(FloatingActionButton, Icons.add);
    expect(fabNovoContato, findsOneWidget);
    await tester.tap(fabNovoContato);
    await tester.pumpAndSettle();

    final contatoFormulario = find.byType(FormularioContato);
    expect(contatoFormulario, findsOneWidget);

    final nomeTextField = find.byWidgetPredicate((widget) {
      if (widget is TextField) {
        return widget.decoration.labelText == 'Nome Completo';
      }
      return false;
    });
    expect(nomeTextField, findsOneWidget);
    await tester.enterText(nomeTextField, 'Heron');

    final numeroContaTextField = find.byWidgetPredicate((widget) {
      if (widget is TextField) {
        return widget.decoration.labelText == 'Número da Conta';
      }
      return false;
    });
    expect(numeroContaTextField, findsOneWidget);
    await tester.enterText(nomeTextField, '1000');

    final createButton = find.widgetWithText(RaisedButton, 'Novo');
    expect(createButton, findsOneWidget);
    await tester.tap(createButton);
    await tester.pumpAndSettle();

    final listaContatoBack = find.byType(ListaContato);
    expect(listaContatoBack, findsOneWidget);
  });
}

Mas retorna o erro

EXCEPTION CAUGHT BY FLUTTER TEST FRAMEWORK The following TestFailure object was thrown running a test: Expected: exactly one matching node in the widget tree Actual: _WidgetTypeFinder:<zero widgets with type "ListaContato" (ignoring offstage widgets)> Which: means none were found but one was expected

When the exception was thrown, this was the stack:

#4 main. (file:///F:/Heron/Flutter/APP-Flutter-Curso-Alura/Curso%202/banco/test/save_contato_test.dart:62:5)

#5 main. (file:///F:/Heron/Flutter/APP-Flutter-Curso-Alura/Curso%202/banco/test/save_contato_test.dart)

#6 testWidgets.. (package:flutter_test/src/widget_tester.dart:140:29)

#7 testWidgets.. (package:flutter_test/src/widget_tester.dart)

#8 TestWidgetsFlutterBinding.runTestBody (package:fluttertest/src/binding.dart:706:19)

#11 TestWidgetsFlutterBinding.runTest (package:fluttertest/src/binding.dart:686:14)

#12 AutomatedTestWidgetsFlutterBinding.runTest. (package:flutter_test/src/binding.dart:1086:24)

#18 AutomatedTestWidgetsFlutterBinding.runTest (package:flutter_test/src/binding.dart:1083:15)

#19 testWidgets. (package:flutter_test/src/widget_tester.dart:133:24)

#20 Declarer.test... (package:test_api/src/backend/declarer.dart:172:27)

#21 Declarer.test... (package:test_api/src/backend/declarer.dart)

#22 Invoker.waitForOutstandingCallbacks. (package:test_api/src/backend/invoker.dart:246:15)

#27 Invoker.waitForOutstandingCallbacks (package:test_api/src/backend/invoker.dart:243:5)

#28 Declarer.test.. (package:test_api/src/backend/declarer.dart:170:33)

#33 Declarer.test. (package:test_api/src/backend/declarer.dart:169:13)

#34 Invoker.onRun.... (package:testapi/src/backend/invoker.dart:400:25) (elided 31 frames from class FakeAsync, class _RawReceivePortImpl, class _Timer, dart:async, dart:async-patch, and package:stacktrace)

This was caught by the test expectation on the following line: file:///F:/Heron/Flutter/APP-Flutter-Curso-Alura/Curso%202/banco/test/save_contato_test.dart line 62 The test description was: Salvar Contato

Test failed. See exception logs above. The test description was: Salvar Contato

mas se passar o final listaContatoBack = find.byType(formContato ); ele retorna correto, sendo assim ele não consegue sair da tela de Formulario no teste