@CheckReturnValue
    @BackpressureSupport(BackpressureKind.PASS_THROUGH)
    @SchedulerSupport(SchedulerSupport.NONE)
    @SuppressWarnings("unchecked")
    public static <T> Flowable<T> empty() {
        return RxJavaPlugins.onAssembly((Flowable<T>) FlowableEmpty.INSTANCE);
    }