a single app.main() in flutter; How to run all tests using method?

Question

I'm trying to write an integration test for my Flutter app I don't want to call the app.main() method over and over for each test a single app.main() in flutter; How to run all tests using method?

 group('Test', () {
    testWidgets('Test 1', (tester) async {
      app.main();
      
    }
    testWidgets('Test 2', (tester) async {
      app.main();
      
    }
}