|  | // @dart = 2.9 | 
|  | import 'dart:async' show FutureOr; | 
|  | import 'dart:collection' show LinkedHashMap, LinkedHashSet; | 
|  |  | 
|  | Future<Iterable<int>> iterablefun() async => {}; | 
|  | Future<LinkedHashMap<int, bool>> lhmfun() async => {}; | 
|  | Future<LinkedHashSet<int>> lhsfun() async => {}; | 
|  | Future<Map<int, bool>> mapfun() async => {}; | 
|  | Future<Set<int>> setfun() async => {}; | 
|  | FutureOr<Iterable<int>> iterablefun2() => {}; | 
|  | FutureOr<LinkedHashMap<int, bool>> lhmfun2() => {}; | 
|  | FutureOr<LinkedHashSet<int>> lhsfun2() => {}; | 
|  | FutureOr<Map<int, bool>> mapfun2() => {}; | 
|  | FutureOr<Set<int>> setfun2() => {}; | 
|  | main() async {} |