private String produceRelyingPartyToken(final HttpServletRequest request, final Service targetService,
                                            final WSFederationRequest fedRequest, final SecurityToken securityToken,
                                            final TicketValidationResult assertion) throws Exception {
        val service = findAndValidateFederationRequestForRegisteredService(targetService, fedRequest);
        LOGGER.debug("Located registered service [{}] to create relying-party tokens...", service);
        return getConfigContext().getRelyingPartyTokenProducer().produce(securityToken, service, fedRequest, request, assertion);
    }
Handle federation request.

@param response the response
@param request  the request
@return the model and view
@throws Throwable the throwable
support/cas-server-support-ws-idp/src/main/java/org/apereo/cas/ws/idp/web/WSFederationValidateRequestCallbackController.java