class FromPublisherStageFactory implements PublisherStageFactory<Stage.PublisherStage> {

    @SuppressWarnings("unchecked")
    @Override
    public <O> PublisherStage<O> create(Engine engine, Stage.PublisherStage stage) {
        Publisher<O> publisher = (Publisher<O>) Objects.requireNonNull(Objects.requireNonNull(stage.getRsPublisher()));
        return () -> Flowable.fromPublisher(publisher);
    }

}