anchor.diff:                  match this with
                   | INodeContent n -> n.IsAttribute
                   | _ -> false
  +
  +            member this.AttributeValue =
  +                match this with
  +                | INodeContent n -> n.AttributeValue
  +                | _ -> None
  +
  +            member this.Name =
  +                match this with
  +                | INodeContent n -> n.Name
  +                | TagContent tc -> Some tc.Name
  +                | TextContent _
  +                | VerbatimContent _
  +                | CommentContent _ -> None
   
               member this.Requires =
                   match this with
  
positive.code:     let NewAttr name value =
          {
              Name = name
              Value = fun _ -> value
              Annotation = None
          }
  
  
negative.code:                 | Some a -> a.Requires
  
              member this.Write(meta, w) =
                  w.WriteAttribute(this.Name, this.Value)
  
              member this.Encode(meta, json) =
                  []
  