Multicast-example.ts

const observable = Rx.Observable.interval(1000).take(5);  
    const observerA = {...};
    const observerB = {...};

    const subject = new Rx.Subject();

    observable.subscribe(subject);

    subject.subscribe(observerA); // first execution
    setTimeout(() => {
      subject.subscribe(observerB); // the same execution
    }, 2000);