anchor.diff:                                     {'retry-after', <<"120">>}, {'route', <<"<sip:server10.biloxi.com;lr>">>},
                                      {'server', <<"HomeServer v2">>}, {'subject', <<"Need more boxes">>},
                                      {'supported', <<"100rel">>}, {'timestamp', <<"54">>},
  +                                   {'to', <<"sip:bob@localhost">>}, {'unsupported', <<"bar, baz">>},
   
   
                                      {'content-length', <<"5">>}, {'via', <<"SIP/2.0/UDP localhost">>},
  -                                   {'to', <<"sip:bob@localhost">>},
  +
                                      {'x-custom-atom', 25},
                                      {'allow', <<"INVITE, ACK, CANCEL, OPTIONS, BYE">>},
  -                                   {'unsupported', <<"bar, baz">>},
                                      {<<"X-Custom">>, <<"value">>}])),
   
        % Already parsed
  
positive.code: 
  
  %% ....
  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);
  
  %% ...
  process(fn, 'unsupported', _Ignore) -> <<"Unsupported">>;
  process(p, 'unsupported', Bin) ->
  
negative.code:      ?_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">>)),
  