title: How to create an empty group in ng-grid
body: <p>I know that ng-grid uses aggregation to group rows[1], so it's not officially supported.</p>
  
  <p>Is there a nice workaround to create a header of aggregation without a row? Or way to use an empty row and don't display it?</p>
  
  <p>I need to aggregate users by group, but I have to list all groups without users too. </p>
  
  <p>Something like:</p>
  
  <p>Group 1 (users : 5)
  -User 1
  -User 2
  -User 3
  -User 4
  -User 5
  Group 2 (users: 0)
  Group 3 (users: 1)
  - User 6</p>
  
  <p>[1] <a href="https://stackoverflow.com/questions/16015088/how-to-set-aggregation-with-grouping-in-ng-grid">How to set aggregation with grouping in ng-grid</a></p>