anchor.diff:  %% http://tools.ietf.org/html/rfc3261#section-20.16
   process(fn, 'cseq', _Ignore) -> <<"CSeq">>;
   process(p, 'cseq', Bin) ->
  -    {SeqBin, Bin2} = sip_syntax:parse_token(Bin),
  +    {Sequence, Bin2} = sip_syntax:parse_integer(Bin),
       {MethodBin, <<>>} = sip_syntax:parse_token(Bin2),
  -    Sequence = sip_binary:binary_to_integer(SeqBin),
       Method = sip_syntax:parse_name(sip_binary:to_upper(MethodBin)),
       cseq(Sequence, Method);
   
  
positive.code: %% http://tools.ietf.org/html/rfc3261#section-20.43
  process(fn, 'warning', _Ignore) -> <<"Warning">>;
  process(p, 'warning', Bin) ->
      {CodeBin, Bin2} = sip_syntax:parse_token(Bin),
      Code = sip_binary:binary_to_integer(CodeBin),
      {Agent, Bin3} = sip_binary:parse_until(Bin2, fun sip_syntax:is_space_char/1),
      {Text, Rest} = sip_syntax:parse_quoted_string(Bin3),
      parse_list('warning', warning(Code, Agent, Text), Rest);
  
  
negative.code: %% http://tools.ietf.org/html/rfc3261#section-20.24
  process(fn, 'mime-version', _Ignore) -> <<"MIME-Version">>;
  process(p, 'mime-version', Bin) ->
      {Major, <<$., MinorBin/binary>>} = sip_syntax:parse_integer(Bin),
      {Major, sip_binary:binary_to_integer(MinorBin)};
  
  process(f, 'mime-version', {Major, Minor}) ->
      MajorBin = sip_binary:integer_to_binary(Major),
  