|  | // Copyright (c) 2013, 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. | 
|  |  | 
|  | import "package:expect/expect.dart"; | 
|  | import "dart:collection"; | 
|  |  | 
|  | void main() { | 
|  | Set s = new HashSet(); | 
|  | s.add(1); | 
|  | Expect.equals("{1}", s.toString()); | 
|  | s.remove(1); | 
|  | s.add(s); | 
|  | Expect.equals("{{...}}", s.toString()); | 
|  |  | 
|  | Queue q = new ListQueue(4); | 
|  | q.add(1); | 
|  | q.add(2); | 
|  | q.add(q); | 
|  | q.add(s); | 
|  |  | 
|  | Expect.equals("{1, 2, {...}, {{...}}}", q.toString()); | 
|  |  | 
|  | // Throwing in the middle of a toString does not leave the | 
|  | // set as being visited | 
|  | q.addLast(new ThrowOnToString()); | 
|  | Expect.throws(q.toString, (e) => e == "Bad!"); | 
|  | q.removeLast(); | 
|  | Expect.equals("{1, 2, {...}, {{...}}}", q.toString()); | 
|  | } | 
|  |  | 
|  | class ThrowOnToString { | 
|  | String toString() { | 
|  | throw "Bad!"; | 
|  | } | 
|  | } |