anchor.diff:  }
   
   void main() {
  -  group("Testability", () {
  +  group('Testability', () {
       Testability testability;
       MockCallback callback;
       MockCallback callback2;
  
positive.code: @TestOn('browser')
  library angular2.test.core.testability.testability_test;
  
  import "dart:async";
  
  import "package:angular2/src/core/di.dart" show Injectable;
  import "package:angular2/src/core/testability/testability.dart"
      show Testability;
  import "package:angular2/src/core/zone/ng_zone.dart" show NgZone;
  import "package:angular2/src/facade/async.dart" show EventEmitter;
  import "package:angular2/src/testing/internal.dart";
  import 'package:mockito/mockito.dart';
  import 'package:test/test.dart';
  
  
negative.code:       test(
            'should fire whenstable callback with didWork '
            'if event is already finished', () async {
          ngZone.unstable();
          ngZone.stable();
          testability.whenStable((value) => callback.execute(value));
          microTask(() {
            verify(callback.execute(true)).called(1);
            testability.whenStable((value) => callback2.execute(value));
            microTask(() {
              verify(callback2.execute(false)).called(1);
            });
          });
        });
        test('should fire whenstable callback with didwork when event finishes',
            () async {
          ngZone.unstable();
          testability.whenStable((value) => callback.execute(value));
          microTask(() {
            ngZone.stable();
            microTask(() {
              verify(callback.execute(true)).called(1);
              testability.whenStable((value) => callback2.execute(value));
              microTask(() {
                verify(callback2.execute(false)).called(1);
              });
            });
          });
  