JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://cdnjs.cloudflare.com/ajax/libs/rxjs/5.0.1/Rx.js"></script>

JavaScript

var source = Rx.Observable.interval(1000).take(3);

var observerA = {
    next: value => console.log('A next: ' + value),
    error: error => console.log('A error: ' + error),
    complete: () => console.log('A complete!')
}

var observerB = {
    next: value => console.log('B next: ' + value),
    error: error => console.log('B error: ' + error),
    complete: () => console.log('B complete!')
}

var subject = new Rx.Subject()

subject.subscribe(observerA)

source.subscribe(subject);

setTimeout(() => {
    subject.subscribe(observerB);
}, 1000);