anchor.diff:  /// The container to register visitors for separate AST node types.
   class NodeLintRegistry {
     final bool enableTiming;
  +  final List<_Subscription<Annotation>> _forAnnotation = [];
     final List<_Subscription<AsExpression>> _forAsExpression = [];
     final List<_Subscription<AssertInitializer>> _forAssertInitializer = [];
     final List<_Subscription<AssertStatement>> _forAssertStatement = [];
  
positive.code:   final LintRuleExceptionHandler exceptionHandler;
  
    LinterVisitor(this.registry, this.exceptionHandler);
  
    @override
    void visitAsExpression(AsExpression node) {
  
negative.code: 
    NodeLintRegistry(this.enableTiming);
  
    void addAnnotation(LintRule linter, AstVisitor visitor) {
      _forAnnotation.add(new _Subscription(linter, visitor, _getTimer(linter)));
    }
  
    void addAsExpression(LintRule linter, AstVisitor visitor) {
      _forAsExpression.add(new _Subscription(linter, visitor, _getTimer(linter)));
    }
  