anchor.diff:    app.configuration.port = 8080;
   
     tearDownAll(() async {
  -    await app.stop();
  +    await app?.stop();
     });
   
     group("Application lifecycle", () {
  
positive.code:     });
  
      test("Application stops", () async {
        await app.stop();
  
        try {
  
negative.code:         expect(e, isNotNull);
        }
  
        print("Restart");
  
        await app.start();
        var resp = await http.get("http://localhost:8080/t");
        expect(resp.statusCode, 200);
        print("stop 2");
        await app.stop();
        print("stop 3");
      });
    });
  
  