anchor.diff:       ?_assertEqual([{'content-length', <<"5">>}, {'via', <<"SIP/2.0/UDP localhost">>},
                       {'from', <<"sip:alice@localhost">>}, {'to', <<"sip:bob@localhost">>},
                       {'call-id', <<"callid">>}, {'contact', <<"Alice <sip:example.com>">>},
  -                    {'supported', <<"100rel">>}, {'content-encoding', <<"gzip">>}],
  -                   parse_headers(<<"l: 5\r\nv: SIP/2.0/UDP localhost\r\nf: sip:alice@localhost\r\n",
  -                                   "t: sip:bob@localhost\r\ni: callid\r\nm: Alice <sip:example.com>\r\n",
  -                                   "k: 100rel\r\ne: gzip\r\n">>)),
  +                    {'supported', <<"100rel">>}, {'content-encoding', <<"gzip">>},
  +                    {'content-type', <<"application/sdp">>}],
  +                   parse_headers(<<"l: 5\r\nv: SIP/2.0/UDP localhost\r\n",
  +                                   "f: sip:alice@localhost\r\nt: sip:bob@localhost\r\n",
  +                                   "i: callid\r\nm: Alice <sip:example.com>\r\n",
  +                                   "k: 100rel\r\ne: gzip\r\n",
  +                                   "c: application/sdp\r\n">>)),
        % multi-line headers
        ?_assertEqual([{'subject', <<"I know you're there, pick up the phone and talk to me!">>}],
                      parse_headers(<<"Subject: I know you're there,\r\n               pick up the phone   \r\n               and talk to me!\r\n">>)),
  
positive.code:                                    {'authorization', <<"Digest username=\"Alice\"">>}, {'call-id', <<"callid">>},
                                     {'call-info', <<"<http://www.example.com/alice/photo.jpg>">>}, {'contact', <<"*">>},
                                     {'content-disposition', <<"session">>}, {'content-encoding', gzip},
                                     {'content-language', 'en'}, {'content-length', 5},
  
                                     {'content-length', <<"5">>}, {'via', <<"SIP/2.0/UDP localhost">>},
                                     {'from', <<"sip:alice@localhost">>}, {'to', <<"sip:bob@localhost">>},
  
negative.code:             Port -> <<Bin/binary, ?SP, Host/binary, ?HCOLON, (sip_binary:integer_to_binary(Port))/binary>>
          end,
      append_params(Bin2, Via#sip_hdr_via.params);
  
  %% ....
  process(fn, 'max-forwards', _Ignore) -> <<"Max-Forwards">>;
  