if (interceptors == null) interceptors = Collections.emptyList();
if (interceptors == null) { interceptors = Collections.emptyList(); }
    public Collection<Interceptor> getInterceptors(LifecycleStage stage) {        Collection<Interceptor> interceptors = this.interceptors.get(stage);        if (interceptors == null) interceptors = Collections.emptyList();        return interceptors;    }