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

tried show 3 notification in cluster format. per doc, added setgroupsummary(true) property first notification.but in result have got 2 notification. notification added groupsummary property not visible.

notificationcompat.builder firstnotification = createnotification(context,"1.message","here go 1"); firstnotification .setgroupsummary(true); firstnotification .setgroup("key_notification_group"); notificationcompat.builder secondnotifi = createnotification(context,"2.message","here go 2"); secondnotifi .setgroup("key_notification_group");            notificationcompat.builder thirdnotifi= createnotification(context,"3.message","here go 3"); thirdnotifi.setgroup("key_notification_group"); 

here 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 result is,

i want show 3 notification in cluster format without missing.

any appreciated.

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

you have create separate group notification , set group summary flag true that, , becomes parent notification bundles other notifications same group key within itself.