Method on

harmony/pushy/src/main/ets/EventHub.ts:19–24

(event: string, callback: EventCallback)

  }

  public on(event: string, callback: EventCallback): void {
    if (!this.listeners.has(event)) {
      this.listeners.set(event, new Set());
    }
    this.listeners.get(event)?.add(callback);
  }

  public off(event: string, callback: EventCallback): void {
    this.listeners.get(event)?.delete(callback);