(request)
RFC 2965, section 3.3.6:

        An unverifiable transaction is to a third-party host if its request-
        host U does not domain-match the reach R of the request-host O in the
        origin transaction.
def is_third_party(request):
    """

    RFC 2965, section 3.3.6:

        An unverifiable transaction is to a third-party host if its request-
        host U does not domain-match the reach R of the request-host O in the
        origin transaction.

    """
    req_host = request_host(request)
    if not domain_match(req_host, reach(request.origin_req_host)):
        return True
    else:
        return False
def is_third_party ( request ) : req_host = request_host ( request ) if not domain_match ( req_host , reach ( request . origin_req_host ) ) : return True else : return False