anchor.diff:      }
     }
   
  +  @override
  +  void visitExtendsClause(ExtendsClause node) {
  +    inExtendsClause = true;
  +    return super.visitExtendsClause(node);
  +  }
  +
     /// Return `true` if the [identifier] is composed of one or more underscore
     /// characters and nothing else.
     bool _isUnused(String identifier) => RegExp(r'^_+$').hasMatch(identifier);
  
positive.code: 
    @override
    void declaredMixin(MixinDeclaration declaration) {
      if (visibilityTracker._isVisible(declaration.declaredElement) &&
          opType.includeTypeNameSuggestions) {
        builder.suggestClass(declaration.declaredElement, kind: _defaultKind);
      }
  
negative.code: 
    /// A flag indicating whether local fields should be suggested.
    final bool suggestLocalFields;
  
    /// A flag indicating whether suggestions are being made inside an `extends`
    /// clause.
    bool inExtendsClause = false;
  
    /// Only used when [useNewRelevance] is `false`.
    int privateMemberRelevance = DART_RELEVANCE_DEFAULT;
  