apollo-biz/src/main/java/com/ctrip/framework/apollo/biz/service/AppService.java/AppService/save
class AppService:  @Transactional
  public App save(App entity) {
    if (!isAppIdUnique(entity.getAppId())) {
      throw new ServiceException("appId not unique");
    }
    entity.setId(0);//protection
    App app = appRepository.save(entity);

    auditService.audit(App.class.getSimpleName(), app.getId(), Audit.OP.INSERT,
        app.getDataChangeCreatedBy());

    return app;
  }