anchor.diff:  -spec xml_sort(item() | [item()]) -> item() | [item()].
   xml_sort(#xmlcdata{} = Cdata) ->
       Cdata;
  -xml_sort(#xmlel{} = El) ->
  -    #xmlel{ attrs = Attrs, children = Children } = El,
  +xml_sort(#xmlel{ attrs = Attrs, children = Children } = El) ->
       El#xmlel{
         attrs = lists:sort(Attrs),
         children = [ xml_sort(C) || C <- Children ]
  
positive.code:          xml_size/1,
           xml_sort/1,
           to_pretty_iolist/1]).
  
  -export([]).
  
  -export_type([attr/0,
                cdata/0,
  
negative.code:     to_binary_nif(Element, Pretty);
  to_iolist([Element], Pretty) ->
      to_iolist(Element, Pretty);
  to_iolist([Head | _] = Elements, Pretty) ->
      [Last | RevChildren] = lists:reverse(tl(Elements)),
      case {Head, Last} of
          {#xmlstreamstart{name = Name, attrs = Attrs},
  