Method on

src/utils/event-emitter.ts:18–23

(eventName: EventType, callback: Callback)

  }

  on(eventName: EventType, callback: Callback) {
    if (!this.events[eventName]) {
      this.events[eventName] = [];
    }
    this.events[eventName].push(callback);
  }

  emit(eventName: EventType) {
    const callbacks = this.events[eventName];