Notification with setGroupSummary(true) is not visible in Android N

Question

Tried to show 3 notification in cluster format. As per the doc, I added the setGroupSummary(true) property for the first notification.But in the result i have got only two notification. The notification which is added the GroupSummary property is not visible.

NotificationCompat.Builder firstNotification = createNotification(context,"1.Message","Here you go 1");
firstNotification .setGroupSummary(true);
firstNotification .setGroup("KEY_NOTIFICATION_GROUP");
NotificationCompat.Builder secondNotifi = createNotification(context,"2.Message","Here you go 2");
secondNotifi .setGroup("KEY_NOTIFICATION_GROUP");           
NotificationCompat.Builder thirdNotifi= createNotification(context,"3.Message","Here you go 3");
thirdNotifi.setGroup("KEY_NOTIFICATION_GROUP");

Here the notification trigger,

notificationManager =   (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
notificationManager.notify(0,firstNotification .build());
notificationManager.notify(1,secondNotifi .build());
notificationManager.notify(2,thirdNotifi.build());

And the result is,

I want to show all three notification in the cluster format without missing.

Any help will be really appreciated.

Answer 1

You should check the following answer : setgroup() in notification not working

You have to create a separate group notification and set the group summary flag true only for that, and that becomes the parent notification that bundles other notifications with the same group key within itself.