main.dart

// Erweitere die Klasse string um die NumberParsing Extension
extension StringParsing on String {
  String changeDirection() {
    return this.split('').reversed.join();
  }
  // ···
}

class Person {
  String name = '';
  Person({required this.name}) {}
  String get reverseName {
    return name.changeDirection();
  }
}

void main() async {
  
  Future<String> waitForReverse(Person person) {
    return Future.delayed(Duration(seconds: 2), () {
      return person.reverseName;
    });
  }
  
  var name = Person(name: "Marcel");
  print(new DateTime.now().toString());
  var val = await waitForReverse(name);
  print('$val');
  print(new DateTime.now().toString());
}