anchor.diff:          if (melement != null &&
               melement.element.node != null &&
               melement.element.node is AnnotatedNode) {
  -          return (melement.element.node as AnnotatedNode).documentationComment.references;
  +          var docComment = (melement.element.node as AnnotatedNode).documentationComment;
  +          if (docComment != null) return docComment.references;
  +          return null;
           }
         }
         if (element.node is AnnotatedNode) {
  
positive.code:   bool get isGetter => _accessor.isGetter;
  
    @override
    String get _href => '${library.name}/${_accessor.enclosingElement.name}/$name.html';
  }
  
  /// Top-level variables. But also picks up getters and setters?
  
negative.code:   String toString() => element.name;
  
    @override
    String get _href => '${library.name}/${_typeParameter.enclosingElement.name}/$name';
  }
  
  class ElementType {
  