anchor.diff:  
     NodeLintRegistry(this.enableTiming);
   
  +  void addAdjacentStrings(LintRule linter, AstVisitor visitor) {
  +    _forAdjacentStrings.add(_Subscription(linter, visitor, _getTimer(linter)));
  +  }
  +
     void addAnnotation(LintRule linter, AstVisitor visitor) {
       _forAnnotation.add(_Subscription(linter, visitor, _getTimer(linter)));
     }
   
  +  void addArgumentList(LintRule linter, AstVisitor visitor) {
  +    _forArgumentList.add(_Subscription(linter, visitor, _getTimer(linter)));
  +  }
  +
     void addAsExpression(LintRule linter, AstVisitor visitor) {
       _forAsExpression.add(_Subscription(linter, visitor, _getTimer(linter)));
     }
  
positive.code:   void visitNamedExpression(NamedExpression node) {
      _runSubscriptions(node, registry._forNamedExpression);
      super.visitNamedExpression(node);
    }
  
    @override
  
negative.code: /// The container to register visitors for separate AST node types.
  class NodeLintRegistry {
    final bool enableTiming;
    final List<_Subscription<AdjacentStrings>> _forAdjacentStrings = [];
    final List<_Subscription<Annotation>> _forAnnotation = [];
    final List<_Subscription<ArgumentList>> _forArgumentList = [];
    final List<_Subscription<AsExpression>> _forAsExpression = [];
    final List<_Subscription<AssertInitializer>> _forAssertInitializer = [];
    final List<_Subscription<AssertStatement>> _forAssertStatement = [];
  