if (DELEGATION_TOKEN_OPS.contains(op) &&
!request.getMethod().equals("OPTIONS")) {
DelegationTokenOperation dtOp =
DelegationTokenOperation.valueOf(op);
if (dtOp.getHttpMethod().equals(request.getMethod())) {
if (dtOp.requiresKerberosCredentials() && token == null) {
response.sendError(HttpServletResponse.SC_UNAUTHORIZED,
MessageFormat.format(
"Operation [{0}] requires SPNEGO authentication established",
dtOp));
requestContinues = false;