anchor.diff:       ?_assertEqual([foo, bar], parse('unsupported', <<"foo, bar">>)),
        ?_assertEqual(<<"foo, bar">>, format('unsupported', [foo, bar])),
   
  +     % User-Agent
  +     ?_assertEqual(<<"Softphone Beta1.5">>, parse('user-agent', <<"Softphone Beta1.5">>)),
  +     ?_assertEqual(<<"Softphone Beta1.5">>, format('user-agent', <<"Softphone Beta1.5">>)),
   
   
        % Via
  
positive.code:                                    {'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">>},
  
                                     {'x-custom-atom', 25},
                                     {'allow', <<"INVITE, ACK, CANCEL, OPTIONS, BYE">>},
                                     {<<"X-Custom">>, <<"value">>}])),
  
       % Already parsed
  
negative.code:                      "Server: HomeServer v2\r\nSubject: Need more boxes\r\n",
                       "Supported: 100rel\r\nTimestamp: 54\r\n",
                       "To: sip:bob@localhost\r\nUnsupported: bar, baz\r\n",
                       "User-Agent: Softphone Beta1.5\r\n"
  
                       "Via: SIP/2.0/UDP localhost\r\n",
                       "x-custom-atom: 25\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>">>},
  