RXDart PublishSubject example

gistfile1.txt

```
import 'dart:async';
import 'package:rxdart/rxdart.dart';

void main()  {
    var streamCtrl = PublishSubject<String>(); 
    streamCtrl.stream.listen(observer1);
    streamCtrl.stream.listen(observer2);
    action(streamCtrl.sink);
}

void action(Sink<String> sink){
  sink.add("hello streams");
}

void observer1(String data) async {
    print("observer 1 response: $data");
}

void observer2(String data) async {
    print("observer 2 response: $data");
}

```