Remove AsyncError with Expando.

pkg/scheduled_test/test/substitute_future_test.dart

 // 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.
 
 library substitute_future_test;
 
 import 'dart:async';
 
 import 'package:scheduled_test/src/substitute_future.dart';
 import 'package:unittest/unittest.dart';
@@ skipping 13 matching lines @@
       completer.complete('success');
     });
 
     test('.asStream on error', () {
       expect(future.asStream().toList(), throwsA(equals('error')));
       completer.completeError('error');
     });
 
     test('.then and .catchError on success', () {
       expect(future.then((v) => "transformed $v")
-              .catchError((e) => "caught ${e.error}"),
+              .catchError((error) => "caught ${error}"),
           completion(equals('transformed success')));
       completer.complete('success');
     });
 
     test('.then and .catchError on error', () {
       expect(future.then((v) => "transformed $v")
-              .catchError((e) => "caught ${e.error}"),
+              .catchError((error) => "caught ${error}"),
           completion(equals('caught error')));
       completer.completeError('error');
     });
 
     test('.then with onError on success', () {
       expect(future.then((v) => "transformed $v",
-              onError: (e) => "caught ${e.error}"),
+              onError: (error) => "caught ${error}"),
           completion(equals('transformed success')));
       completer.complete('success');
     });
 
     test('.then with onError on error', () {
       expect(future.then((v) => "transformed $v",
-              onError: (e) => "caught ${e.error}"),
+              onError: (error) => "caught ${error}"),
           completion(equals('caught error')));
       completer.completeError('error');
     });
 
     test('.whenComplete on success', () {
       expect(future.whenComplete(() {
         throw 'whenComplete';
       }), throwsA(equals('whenComplete')));
       completer.complete('success');
     });
@@ skipping 79 matching lines @@
   });
 
   test('substituting after a future has completed is an error', () {
     var completer = new Completer();
     var future = new SubstituteFuture(completer.future);
     completer.complete('success');
     expect(() => future.substitute(new Future.immediate(null)),
         throwsStateError);
   });
 }