anchor.diff:                                     {'allow', <<"INVITE">>}, {'authentication-info', <<"nextnonce=\"47364c23432d2e131a5fb210812c\"">>},
                                      {'authorization', <<"Digest username=\"Alice\"">>}, {'call-id', <<"callid">>},
                                      {'call-info', <<"<http://www.example.com/alice/photo.jpg>">>}, {'contact', <<"*">>},
  -                                   {'content-disposition', <<"session">>},
  +                                   {'content-disposition', <<"session">>}, {'content-encoding', gzip},
   
                                      {'content-length', <<"5">>}, {'via', <<"SIP/2.0/UDP localhost">>},
                                      {'from', <<"sip:alice@localhost">>}, {'to', <<"sip:bob@localhost">>},
  
positive.code:      ?_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">>}],
                     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\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">>)),
  
negative.code:                    format('content-disposition', #sip_hdr_disposition{type = 'icon', params = [{handling, optional}, {param, value}]})),
  
  
       % Content-Encoding
       ?_assertEqual([gzip, tar], parse('content-encoding', <<"gzip, tar">>)),
       ?_assertEqual(<<"gzip, tar">>, format('content-encoding', [gzip, tar])),
  
  
  
  