protected void storeAuthenticationRequest(final HttpServletRequest request, final HttpServletResponse response,
                                              final Pair<? extends SignableSAMLObject, MessageContext> context) {
        lock.tryLock(__ -> {
            val webContext = new JEEContext(request, response);
            SamlIdPSessionManager.of(configurationContext.getOpenSamlConfigBean(),
                configurationContext.getSessionStore()).store(webContext, context);
        });
    }
Handle SAML2 exceptions.

@param req the req
@param ex  the ex
@return the model and view
support/cas-server-support-saml-idp-web/src/main/java/org/apereo/cas/support/saml/web/idp/profile/AbstractSamlIdPProfileHandlerController.java