anchor.diff:    final int variable;
     final List<Edge> inputs = <Edge>[];
     final List<Edge> outputs = <Edge>[];
  +  final List<Annotation> annotations = <Annotation>[];
   
     /// The annotation to show when visualized in the context of a given member.
     final Map<Member, Annotation> annotationForContext = <Member, Annotation>{};
  
positive.code:     // TODO(asgerf): If we use these annotations for testing, the necessary
      //   bindings should arguably be part of the API for the Builder.
      visualizer.variableNodes.forEach((int variable, GraphNode node) {
        for (Annotation annotation in node.annotationForContext.values) {
          if (annotation.node is VariableDeclaration && annotation.info == null) {
            variables[annotation.node] = variable;
          }
  
negative.code:   }
  
    void addAnnotation(Member member, TreeNode astNode, String info) {
      var annotation = new Annotation(astNode, info);
      annotations.add(annotation);
      annotationForContext[member] = annotation;
    }
  }
  
  