title: Group notifications on Android
body: <p>I want to show notifications like on picture. If there is more than one, I want to show a counter too. I didn't find info in official doc. Now I just update my notification by id:</p>
  
  <pre><code>((NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE))
                  .notify(PUSH_NOTIFICATION_ID, notification);
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/atuoJ.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/atuoJ.png" alt="notification example"></a></p>
  
  <p>How can I do it ?</p>