anchor.diff:       ?_assertEqual(<<"54.3 2.6">>, format('timestamp', timestamp(54.3, 2.6))),
        ?_assertEqual(<<"54.3">>, format('timestamp', timestamp(54.3, 0.0))),
   
  -
        % To
        ?_assertEqual(address(<<"Bob Zert">>, <<"sip:bob@biloxi.com">>, [{'tag', <<"1928301774">>}]),
                      parse('to', <<"\"Bob Zert\" <sip:bob@biloxi.com>;tag=1928301774">>)),
  
positive.code:                      "Retry-After: 120\r\nRoute: <sip:server10.biloxi.com;lr>\r\n",
                       "Server: HomeServer v2\r\nSubject: Need more boxes\r\n",
                       "Supported: 100rel\r\nTimestamp: 54\r\n",
  
                       "Content-Length: 5\r\nVia: SIP/2.0/UDP localhost\r\n",
                       "To: sip:bob@localhost\r\n"
                       "x-custom-atom: 25\r\nAllow: INVITE, ACK, CANCEL, OPTIONS, BYE\r\n",
                       "Unsupported: bar, baz\r\n",
                       "X-Custom: value\r\n">>,
                     format_headers([{'accept', <<"*/*">>}, {'accept-encoding', <<"identity">>},
                                     {'accept-language', <<"en">>}, {'alert-info', <<"<http://www.example.com/sounds/moo.wav>">>},
  
negative.code:             <<Bin/binary, ?SP, DelayBin/binary>>
      end;
  
  %% 20.39 To
  %% http://tools.ietf.org/html/rfc3261#section-20.38
  process(pn, <<"t">>, _Ignore) -> 'to';
  process(fn, 'to', _Ignore) -> <<"To">>;
  process(p, 'to', Bin) ->
      {Top, <<>>} = parse_address(Bin, fun parse_generic_param/2),
      Top;
  
  process(f, 'to', Addr) when is_record(Addr, sip_hdr_address) ->
      format_address(Addr);
  
  
  
  %% .....
  