anchor.diff:  
        % Content-Length
        ?_assertEqual(32543523, parse('content-length', <<"32543523">>)),
  -     ?_assertEqual(<<"98083">>,
  -                   format('content-length', 98083)),
  +     ?_assertEqual(<<"98083">>, format('content-length', 98083)),
        % CSeq
        ?_assertEqual(cseq(1231, 'ACK'), parse('cseq', <<"1231 ACK">>)),
        ?_assertEqual(<<"123453 INVITE">>, format('cseq', cseq(123453, 'INVITE'))),
  
positive.code: header_name_to_binary('contact') -> <<"Contact">>;
  header_name_to_binary('allow') -> <<"Allow">>;
  header_name_to_binary('require') -> <<"Require">>;
  header_name_to_binary('supported') -> <<"Supported">>;
  header_name_to_binary('unsupported') -> <<"Unsupported">>;
  header_name_to_binary(Name) when is_binary(Name) -> Name;
  
negative.code:                    parse('allow', <<"INVITE, ACK, CANCEL, OPTIONS, BYE">>)),
       ?_assertEqual(<<"INVITE, ACK, CANCEL, OPTIONS, BYE">>,
                     format('allow', ['INVITE', 'ACK', 'CANCEL', 'OPTIONS', 'BYE'])),
  
       % Require, Proxy-Require, Supported, Unsupported
       ?_assertEqual([foo, bar], parse('require', <<"foo, bar">>)),
       ?_assertEqual(<<"foo, bar">>, format('require', [foo, bar])),
  
       ?_assertEqual([foo, bar], parse('proxy-require', <<"foo, bar">>)),
       ?_assertEqual(<<"foo, bar">>, format('proxy-require', [foo, bar])),
  
       ?_assertEqual([foo, bar], parse('supported', <<"foo, bar">>)),
       ?_assertEqual(<<"foo, bar">>, format('supported', [foo, bar])),
  
       ?_assertEqual([foo, bar], parse('unsupported', <<"foo, bar">>)),
       ?_assertEqual(<<"foo, bar">>, format('unsupported', [foo, bar])),
  
       % Subject (FIXME: implement proper tests)
       ?_assertEqual(<<"I know you're there, pick up the phone and talk to me!">>,
  