future5.dart

void future_wait(String url1, String url2) {
  Future.wait([
      http.get(url1),
      http.get(url2),
      Future.error('Future.error()'),
    ],
    cleanUp: (value) { print('CleanUp() : ${value?.statusCode}'); }
  ).then((value) {
    for (var f in value) {
      print('statusCode: ${f?.statusCode}');
    }
  }).catchError((error) { print('error : $error'); });
}

// output
// CleanUp() : 200
// CleanUp() : 200
// error : Future.error()

// ouput
// statusCode: 200
// statusCode: 200