private static boolean isValidFlowId(final String flowId) {
        return !StringUtils.startsWithIgnoreCase(flowId, "webjars/")
            && !StringUtils.startsWithIgnoreCase(flowId, "css/")
            && !StringUtils.startsWithIgnoreCase(flowId, "favicon")
            && !StringUtils.startsWithIgnoreCase(flowId, "images/")
            && !StringUtils.startsWithIgnoreCase(flowId, "js/");
    }
This is {@link DefaultCasWebflowIdExtractor}.

@author Misagh Moayyed
@since 7.2.0
core/cas-server-core-webflow-api/src/main/java/org/apereo/cas/web/flow/DefaultCasWebflowIdExtractor.java