|  | // Copyright (c) 2012, 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"; | 
|  |  | 
|  | abstract class A { | 
|  | factory A(int x, int y) = B; | 
|  | } | 
|  |  | 
|  | class B implements A { | 
|  | final int x; | 
|  | final int y; | 
|  |  | 
|  | B(this.x, this.y); | 
|  |  | 
|  | // This factory should never be invoked. | 
|  | factory B.A(int a, int b) { | 
|  | return new B(0, 0); | 
|  | } | 
|  |  | 
|  | factory B.X(int a, int b) { | 
|  | return new B(a * 10, b * 10); | 
|  | } | 
|  | } | 
|  |  | 
|  | main() { | 
|  | var a = new B(1, 2); | 
|  | // Check that constructor B is invoked and not factory B.A. | 
|  | Expect.equals(1, a.x); | 
|  | Expect.equals(2, a.y); | 
|  |  | 
|  | var x = new B.X(11, 22); | 
|  | // Check that factory is invoked. | 
|  | Expect.equals(110, x.x); | 
|  | Expect.equals(220, x.y); | 
|  | } |