code: public static InstanceService getInstanceService() {
      if (instanceService == null) {
        try {
          Class clazz = Class.forName(INSTANCE_SERVICE);
          instanceService = (InstanceService) clazz.newInstance();
        } catch (ClassNotFoundException | InstantiationException | IllegalAccessException e) {
          LOGGER.warn("Cannot instanciate util: {}", e.getMessage());
          throw new IllegalStateException(e);
        }
      }
      return instanceService;
    }
docs: Retrieve InstanceService implementation
  @return InstanceService instance