anchor.diff:  try_amp(_B, _, _Acc) -> 
       false.
   
  +try_comment(<<"-->", Rest/binary>>, Acc) ->
  +    {Rest, <<Acc/binary, "-->">>};
  +try_comment(<<C/utf8, Rest/binary>>, Acc) ->
  +    try_comment(Rest, <<Acc/binary, C/utf8>>);
  +try_comment(_B, _Acc) ->
  +    false.
   
   is_valid_ent_char(C) ->
       (C >= $a andalso C =< $z) orelse (C >= $A andalso C =< $Z).
  
positive.code: 
  ensure_escaped_amp(<<>>, Acc) ->
      Acc;
  ensure_escaped_amp(<<$&, Rest/binary>>, Acc) ->
      case try_amp(Rest, in_amp, <<>>) of
          {Amp,Rest1} -> ensure_escaped_amp(Rest1, <<Acc/binary, $&, Amp/binary>>);
  
negative.code: flatten({nop, Enclosed}) ->
      flatten(Enclosed);
  flatten({comment, Text}) ->
      Comment = binary:replace(Text, <<"-->">>, <<"-- >">>, [global]),
      <<"<!--", Comment/binary, "-->">>;
  flatten({sanitized_html, Html}) ->
      Html;
  