ccnokes

const { Observable } = require('rxjs/Observable');
require('rxjs/add/observable/fromEvent');
require('rxjs/add/operator/map');
require('rxjs/add/observable/merge');

function createOnline$() {
  //merge several events into one
  return Observable.merge(
    //use .map() to transform the returned Event type into a true/false value
  	Observable.fromEvent(window, 'offline').map(() => false),