anchor.diff:      final groupName = parameters['groupName'];
   
       final result = instance._nodeToJson(
  -      WidgetsBinding.instance?.renderViewElement?.toDiagnosticsNode(),
  +      WidgetsBinding.instance.renderViewElement?.toDiagnosticsNode(),
         InspectorSerializationDelegate(
           groupName: groupName,
           subtreeDepth: 1000000,
  
positive.code:     throw 'Dummy extension method to make the code type check when it calls private members';
    }
  
    List<String> /*?*/ get _pubRootDirectories {
      throw 'Dummy extension method to make the code type check when it calls private members';
    }
  }
  
negative.code: // widget_inspector.dart library so using protected members is fine.
  // ignore_for_file: invalid_use_of_visible_for_testing_member
  // ignore_for_file: invalid_use_of_protected_member
  
  import 'dart:async';
  import 'dart:convert';
  