export function observerForSocket<T>(map: (t: T) => Buffer,
    port: number,
    address: string,
    socket: dgram.Socket) {
        return Rx.Observer.create<T>(
            t => {
                const buffer = map(t);
                socket.send(buffer, 0, buffer.byteLength, port, address);
            },
            () => socket.close(),
            () => socket.close());
}

 request.end((err, res) => {
   if (err) {
     obs.onError(err)
   } else {
     obs.onNext(res)
   }
   obs.onCompleted()
 })

 ap(...args) {
     let result = this.step.apply(this, args);
     if (this.observer) {
         this.observer.onNext(result);
     }
     return result;
 }

 s1 = s1.doOnNext((val: string) => {
   const action = match(val);
   if (action) {
     observer.onNext(action);
   }
 });

 output.on('action', (obj: Object) => {
   observer.onNext(obj);
 });

 child.on('exit', () => {
   observer.onCompleted();
 });