docs: @RequiresApi(api = Build.VERSION_CODES.O)
    public static void setupNotificationChannel() {
      NotificationManager manager
        = (NotificationManager) getApplicationContext().getSystemService(Context.NOTIFICATION_SERVICE);
      NotificationChannel channel = new NotificationChannel(OfflineConstants.NOTIFICATION_CHANNEL,
        "Offline", NotificationManager.IMPORTANCE_DEFAULT);
      channel.setLightColor(Color.GREEN);
      channel.setLockscreenVisibility(Notification.VISIBILITY_PRIVATE);
      manager.createNotificationChannel(channel);
    }