private void renderException(final Map<String, Object> model, final HttpServletResponse response) {
        response.setStatus(HttpServletResponse.SC_BAD_REQUEST);
        model.put("status", HttpServletResponse.SC_BAD_REQUEST);
        render(model, response);
    }
Render exceptions. Sets the response status accordingly to note bad requests.

@param model    the model
@param response the response
core/cas-server-core-util-api/src/main/java/org/apereo/cas/util/JsonUtils.java