RXjs - hot observable test

//ES 6 code
// const RX = require('rx')

class EventEmitter {
  
  constructor() {
    this.__events = {};
  }
  
  on(eventName, handler) {
    const list = this._eventList(eventName);
    this._addListener(list, handler);
  }
  
  emit(eventName, ...args) {
    this._eventList(eventName).forEach(fn => fn(...args))
  }
  
  _eventList(eventName) {
    if (!this.__events[eventName]) this.__events[eventName] = [];
    return this.__events[eventName];
  }
  
  _addListener(list, handler) {
    list.push(handler);
  }
}


const emitter = new EventEmitter();

const source = Rx.Observable.fromEventPattern(
  v => emitter.on('testEmit', v)
);
source.subscribe(v => console.log(`Subscriber 1 -> ${v}`));

[10, 20, 30, 40, 50].forEach(v => emitter.emit('testEmit', v));


window.setTimeout(() => source.subscribe(v => console.log(`Subscriber 2 -> ${v}`)), 1000);

window.setTimeout(() => emitter.emit('testEmit', 60), 1500);