| // 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"; | 
 |  | 
 | void main() { | 
 |   Expect.equals('', useParameterInClosure(1)); | 
 |   Expect.equals(43, updateParameterInClosure(1)()); | 
 | } | 
 |  | 
 | String useParameterInClosure(arg1, {int? arg2}) { | 
 |   if (arg1 is Map) { | 
 |     return arg1.keys.map((key) => arg1[key]).first; | 
 |   } else { | 
 |     return ''; | 
 |   } | 
 | } | 
 |  | 
 | Function updateParameterInClosure(arg1) { | 
 |   if (arg1 is Map) { | 
 |     return () => arg1 = 42; | 
 |   } else { | 
 |     return () => arg1 = arg1 + 42; | 
 |   } | 
 | } |