anchor.diff:  unescape(B) when is_binary(B) ->
       unescape(B, <<>>).
   
  -unescape(<<>>, Acc) -> 
  +unescape(<<>>, Acc) ->
       Acc;
   unescape(<<"&", Rest/binary>>, Acc) ->
       unescape_in_charref(Rest, <<>>, Acc);
  
positive.code: -spec escape_check(list()|binary()|{trans, list()}) -> binary() | undefined.
  escape_check({trans, Tr}) ->
      {trans, [{Lang, escape_check(V)} || {Lang,V} <- Tr]};
  escape_check(undefined) -> 
      undefined;
  escape_check(<<>>) -> 
      <<>>;
  escape_check([]) ->
      <<>>;
  
negative.code: %% @spec unescape(iolist()) -> binary()
  unescape({trans, Tr}) ->
      {trans, [{Lang, unescape(V)} || {Lang,V} <- Tr]};
  unescape(undefined) ->
      undefined;
  unescape(<<>>) ->
      <<>>;
  unescape([]) ->
      <<>>;
  