| // Copyright (c) 2014, 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. | 
 |  | 
 | class A { | 
 |   final _x; | 
 |   const A.a1( | 
 |     String //# 01: checked mode compile-time error, static type warning | 
 |       x) | 
 |       : this.a2(x); | 
 |   const A.a2( | 
 |     String //# 02: checked mode compile-time error | 
 |       x) | 
 |       : this.a3(x); | 
 |   const A.a3( | 
 |     String //# 03: checked mode compile-time error | 
 |       x) | 
 |       : _x = x; | 
 | } | 
 |  | 
 | use(x) => x; | 
 |  | 
 | main() { | 
 |   use(const A.a1(0)); | 
 | } |