(define (http-get uri)
  (unless (equal? uri
                  (string->uri "https://group-server.example.com/the#group"))
    (exit 1)
    (values
     (build-response #:headers '((content-type text/turtle)))
     "@prefix vcard: <http://www.w3.org/2006/vcard/ns#>.

<#group> a vcard:Group;
  vcard:hasMember <https://other-user.example.com/profile/card#me> .
")))