Verify dom changes every second, reload after 1 minute, send notification if change happened with Tampermonkey and RxJS

dom_check.js

// ==UserScript==
// @name         Verify fitness hut class availability
// @namespace    http://tampermonkey.net/
// @version      0.1
// @description  try to take over the world!
// @author       You
// @match        https://www.myhut.pt/myhut/aulas/*
// @grant        none
// @require https://cdnjs.cloudflare.com/ajax/libs/rxjs/5.4.3/Rx.js
// ==/UserScript==

const interval$ = Rx.Observable.interval(1000);

const borderClasses$ = interval$
  .map(() => document.getElementById('aula-heading468444').parentNode.className)
  .map(borderNode => borderNode !== "panel panel-red");

const isntAvailable$ = borderClasses$
  .filter(x => !x)
  .distinctUntilChanged()
  .do(x => console.log('class unavailable, will reload in one minute'))
  .delay(60000)
  .do(() => location.reload())
  .subscribe();

const isAvailable$ = borderClasses$
  .filter(x => x)
  .do(x => {
    new Notification('Yey!', {
      icon: 'https://image.freepik.com/free-icon/dumbbell-exercise_318-35207.png',
      body: "A aula esta livre :)",
    });
  }).subscribe();