private static void registerListener() {
    SSOToken adminToken = (SSOToken) AccessController.doPrivileged(AdminTokenAction.getInstance());

    EntitlementConfiguration ec =
        EntitlementConfiguration.getInstance(SubjectUtils.createSubject(adminToken), "/");
    if (ec.migratedToEntitlementService()) {
      try {
        ServiceConfigManager scm = new ServiceConfigManager(IdConstants.REPO_SERVICE, adminToken);
        scm.addListener(new SubRealmObserver());
      } catch (SMSException e) {
        PrivilegeManager.debug.error("SubRealmObserver.registerListener", e);
      } catch (SSOException e) {
        PrivilegeManager.debug.error("SubRealmObserver.registerListener", e);
      }
    }
  }