docs: public String setRedirectUrlIfNotDefined(HttpServletRequest req, ConvergedClientConfig clientConfig) {
          //String redirect_url = clientConfig.getRedirectUrlFromServerToClient();
          String redirect_url = null;
          // in oidc case, configimpl completely builds this url, in social we need to finish building it.
          if (clientConfig.isSocial()) {
              redirect_url = getRedirectUrlFromServerToClient(clientConfig.getId(), clientConfig.getContextPath(), clientConfig.getRedirectUrlFromServerToClient());
          } else {
              redirect_url = clientConfig.getRedirectUrlFromServerToClient();
          }
  
          // in oidc and social case, null unless redirectToRPHostAndPort specified.
          if (redirect_url == null || redirect_url.isEmpty()) {
              String uri = clientConfig.getContextPath() + "/redirect/" + clientConfig.getId();
              redirect_url = new OidcClientUtil().getRedirectUrl(req, uri);
          }
          redirect_url = clientConfig.getRedirectUrlWithJunctionPath(redirect_url);
          return redirect_url;
      }