Testing enhanced enums in flutter/dart

I was wondering how would we test any of the new enhanced enums, because based on the lcov report it appears as untested

Example:

// NORMAL ENUMS
enum AppRoutes { myRoute1, myRoute2 } // Does not need testing

// ENHANCED ENUMS
enum EnhancedAppRoutes { // This line does need testing according to lcov report
  myRoute1('route1'),
  myRoute2('route2');

  const EnhancedAppRoutes(this.route); // This one is ok

  final String route;
}

Test file:

void main() {
  group('Enum example', () {
    test('Test enum', () {
      const Enum e1 = EnhancedAppRoutes.myRoute1,
          e2 = EnhancedAppRoutes.myRoute2;

      expect(e1.runtimeType != e2.runtimeType, false);
      expect(Enum.compareByIndex(e1, e2), -1);
    });
  });
}

Lcov.info:

SF:lib/example_enum.dart
DA:2,1
DA:5,0
DA:9,1
LF:3
LH:2
end_of_record

Thanks