code: function Event(type, eventInitDict) {
    this.type = type;
    this.bubbles = eventInitDict.bubbles;
    this.cancelable = eventInitDict.cancelable;
  
    this.target = null;
    this.currentTarget = null;
    this.eventPhase = eventPhases.NONE;
  
    this.timestamp = now();
  }
docs: https://dom.spec.whatwg.org/#event