anchor.diff:  import 'package:angular_test/angular_test.dart';
   import 'package:test/test.dart';
   import 'package:angular/angular.dart';
  -import 'package:angular/src/debug/debug_node.dart';
   
   import 'view_creation_test.template.dart' as ng_generated;
   
  
positive.code:       provide(ANCHOR_ELEMENT, useValue: template),
      ]);
      final testFixture = await testBed.create();
      final nestedDiv = testFixture.rootElement.firstChild.firstChild;
      final viewport = getDebugNode(nestedDiv).inject(SomeImperativeViewport);
      expect(viewport.anchor.text, '');
      await testFixture.update((component) => component.ctxBoolProp = true);
      expect(viewport.anchor.text, 'hello');
  
negative.code: 
  @Directive(
    selector: 'with-prop-decorators',
  )
  class DirectiveWithPropDecorators {
    final StreamController<String> _streamController =
  