* responses numbered 101 to 199 may be sent reliably. If the request did not include
* either a Supported or Require header field indicating this feature, the UAS MUST NOT
* send the provisional response reliably.
*/
if (statusCode <= 100 || statusCode > 199)
throw new InvalidArgumentException("Bad status code ");
SIPRequest request = this.originalRequest;
if (!request.getMethod().equals(Request.INVITE))
throw new SipException("Bad method");
ListIterator<SIPHeader> list = request.getHeaders(SupportedHeader.NAME);