anchor.diff:      Sanitized = sanitize(Parsed, [], ExtraElts, ExtraAttrs, Options),
       flatten(Sanitized).
   
  -sanitize(B, _Stack, _ExtraElts, _ExtraAttrs, Options) when is_binary(B) ->
  -    case sanitize_callback({'TextNode', B}, Options) of
  +sanitize(B, Stack, _ExtraElts, _ExtraAttrs, Options) when is_binary(B) ->
  +    case sanitize_callback({'TextNode', B}, Stack, Options) of
           {'TextNode', B1} -> escape(iolist_to_binary(B1));
           Other -> Other
       end; 
  -sanitize({comment, _Text} = Comment, _Stack, _ExtraElts, _ExtraAttrs, Options) ->
  -    sanitize_callback(Comment, Options);
  +sanitize({comment, _Text} = Comment, Stack, _ExtraElts, _ExtraAttrs, Options) ->
  +    sanitize_callback(Comment, Stack, Options);
   sanitize({pi, _Raw}, _Stack, _ExtraElts, _ExtraAttrs, _Options) ->
       <<>>;
   sanitize({pi, _Tag, _Attrs}, _Stack, _ExtraElts, _ExtraAttrs, _Options) ->
  
positive.code:             Tag = { Elt, 
                      Attrs1,
                      [ sanitize(Encl, Stack1, ExtraElts, ExtraAttrs, Options) || Encl <- Enclosed ]},
              sanitize_callback(Tag, Options);
          false ->
              case skip_contents(Elt) of
                  false ->
  
negative.code:             end
      end.
  
  sanitize_callback(Element, _Stack, Context) when is_tuple(Context), element(1, Context) =:= context ->
      z_notifier:foldl(sanitize_element, Element, Context);
  sanitize_callback(Element, Stack, Options) ->
      case proplists:get_value(element, Options) of
          undefined -> Element;
          {M,F,A} -> erlang:apply(M, F, [Element,Stack|A]);
          F when is_function(F,1) -> F(Element);
          F when is_function(F,2) -> F(Element,Options);
          F when is_function(F,3) -> F(Element,Stack,Options)
      end.
  
  
  