|  | // Copyright (c) 2021, the Dart project authors.  Please see the AUTHORS file | 
|  | // for details. All rights reserved. Use of this source code is governed by a | 
|  | // BSD-style license that can be found in the LICENSE file. | 
|  |  | 
|  | // See https://github.com/dart-lang/sdk/issues/25559 | 
|  |  | 
|  | import "dart:developer"; | 
|  | import "dart:isolate"; | 
|  |  | 
|  | import "package:expect/async_helper.dart"; | 
|  |  | 
|  | main() { | 
|  | asyncStart(); | 
|  | var port; | 
|  | port = new RawReceivePort((message) { | 
|  | var expando = message as Expando; | 
|  |  | 
|  | // Sent and received without error. | 
|  |  | 
|  | port.close(); | 
|  | asyncEnd(); | 
|  | }); | 
|  |  | 
|  | var unwrittenKey = new Object(); | 
|  | var expando = new Expando(); | 
|  | expando[unwrittenKey] = new UserTag("cant send this"); | 
|  |  | 
|  | port.sendPort.send(expando); | 
|  |  | 
|  | print(unwrittenKey); // Ensure [unwrittenKey] is live during [send]. | 
|  | } |