POST /egroupware/groupdav.php/ralf/calendar/1.ics?action=attachment-add HTTP/1.1
Host: ralfsmacbook.local
User-Agent: Test
Authorization: Basic cmFsZjpzZWNyZXQ=
Content-Type: text/html; charset="utf-8"
Content-Disposition:attachment;filename=agenda.html
Content-Length: 54
Prefer: return-representation
Connection: close

<html>
  <body>
    <h1>Agenda</h1>
  </body>
</html>
