RxJava 2.0 - How to convert Observable to Publisher : <p>How to convert Observable to Publisher in RxJava version 2?</p>

<p>In the first version we have the <a href="https://github.com/ReactiveX/RxJavaReactiveStreams" rel="noreferrer">https://github.com/ReactiveX/RxJavaReactiveStreams</a> project that do exactly what I need.
But How can I do it in RxJava 2?</p>
