anchor.diff:        super.visitMethodDeclaration(node);
       });
       resolveMetadata(node, node.metadata, element);
  -    return null;
  -  }
  -
  -  @override
  -  Object visitMixinDeclaration(MixinDeclaration node) {
  +  }
  +
  +  @override
  +  void visitMixinDeclaration(MixinDeclaration node) {
       ClassElement element = _match(node.name, _walker.getMixin());
       _walk(new ElementWalker.forClass(element), () {
         super.visitMixinDeclaration(node);
       });
       resolveMetadata(node, node.metadata, element);
  -    return null;
  -  }
  -
  -  @override
  -  Object visitPartDirective(PartDirective node) {
  +  }
  +
  +  @override
  +  void visitPartDirective(PartDirective node) {
       super.visitPartDirective(node);
       List<ElementAnnotation> annotations =
           _enclosingUnit.getAnnotations(node.offset);
  
positive.code:       annotations = _walker.element.library.parts[index].metadata;
      }
      resolveAnnotations(node, node.metadata, annotations);
      return null;
    }
  
    @override
    Object visitPartOfDirective(PartOfDirective node) {
      node.element = _enclosingUnit.library;
      return super.visitPartOfDirective(node);
    }
  
    @override
    Object visitSimpleFormalParameter(SimpleFormalParameter node) {
      if (node.parent is! DefaultFormalParameter) {
        ParameterElement element =
            _match(node.identifier, _walker.getParameter());
  
negative.code:       annotations = _walker.element.library.metadata;
      }
      resolveAnnotations(node, node.metadata, annotations);
    }
  
    @override
    void visitMethodDeclaration(MethodDeclaration node) {
      Token property = node.propertyKeyword;
      SimpleIdentifier methodName = node.name;
      String nameOfMethod = methodName.name;
  