public CasShibRegisteredService findServiceByAppName(String appName)
      throws CasShibServiceRegistrarException {
    if (!isInitialized) {
      // this shouldn't happen here, but just in case
      initialize();
    }

    for (RegisteredService entry : servicesManager.getAllServices()) {
      if (entry instanceof CasShibRegisteredService && entry.getName().equals(appName)) {
        return ((CasShibRegisteredService) entry);
      }
    }

    return null;
  }