anchor.diff:  
     List<ExecutableElement> get _inheritedElements {
       if (__inheritedElements == null) {
  -      Map<String, ExecutableElement> cmap = definingLibrary.inheritanceManager
  -          .getMembersInheritedFromClasses(// ignore: deprecated_member_use
  -              element);
  -      Map<String, ExecutableElement> imap = definingLibrary.inheritanceManager
  -          .getMembersInheritedFromInterfaces(// ignore: deprecated_member_use
  -              element);
  -      __inheritedElements = List.from(cmap.values)
  -        ..addAll(imap.values.where((e) => !cmap.containsKey(e.name)));
  +      var classElement = element as ClassElement;
  +      var classType = classElement.type;
  +      if (classType.isObject) {
  +        return __inheritedElements = <ExecutableElement>[];
  +      }
  +
  +      var inheritance = definingLibrary.inheritanceManager;
  +      var cmap = inheritance.getInheritedConcreteMap(classType);
  +      var imap = inheritance.getInheritedMap(classType);
  +
  +      var combinedMap = <String, ExecutableElement>{};
  +      for (var nameObj in cmap.keys) {
  +        combinedMap[nameObj.name] = cmap[nameObj];
  +      }
  +      for (var nameObj in imap.keys) {
  +        combinedMap[nameObj.name] ??= imap[nameObj];
  +      }
  +
  +      __inheritedElements = combinedMap.values.toList();
       }
       return __inheritedElements;
     }
  
positive.code:     return '${package.baseHref}${library.dirName}/$fileName';
    }
  
    // ignore: deprecated_member_use
    InheritanceManager _inheritanceManager;
  
    // ignore: deprecated_member_use
    InheritanceManager get inheritanceManager {
      if (_inheritanceManager == null) {
        // ignore: deprecated_member_use
        _inheritanceManager = InheritanceManager(element);
      }
      return _inheritanceManager;
    }
  
negative.code: import 'package:analyzer/src/dart/analysis/performance_logger.dart';
  import 'package:analyzer/src/dart/element/element.dart';
  import 'package:analyzer/src/dart/element/handle.dart';
  import 'package:analyzer/src/dart/element/inheritance_manager3.dart';
  import 'package:analyzer/src/dart/element/member.dart'
      show ExecutableMember, Member, ParameterMember;
  import 'package:analyzer/src/dart/sdk/sdk.dart';
  import 'package:analyzer/src/generated/engine.dart' hide AnalysisResult;
  import 'package:analyzer/src/generated/java_io.dart';
  import 'package:analyzer/src/generated/resolver.dart'
      show Namespace, NamespaceBuilder;
  import 'package:analyzer/src/generated/sdk.dart';
  import 'package:analyzer/src/generated/source.dart';
  import 'package:analyzer/src/generated/source_io.dart';
  