static DelegatedClientNameExtractor fromHttpRequest() {
        return context -> {
            var clientName = context.getParameter(Pac4jConstants.DEFAULT_CLIENT_NAME_PARAMETER);
            var relayState = context.getParameter("RelayState");
            if (StringUtils.isBlank(clientName) && StringUtils.isNotBlank(relayState) && StringUtils.startsWithIgnoreCase(relayState, "http")) {
                clientName = extractClientNameFromRelayStateUrl(relayState);
            }
            return Optional.ofNullable(clientName);
        };
    }
Extract client name from http request parameter.

@return the delegated client name extractor
support/cas-server-support-pac4j-api/src/main/java/org/apereo/cas/pac4j/client/DelegatedClientNameExtractor.java