title: eloquent use ->with() with only retrieving one column?
body: <p>e.g.</p>
  
  <p>i want to retrieve all users with the relation roles, but only the field of role name.</p>
  
  <p>something like this:</p>
  
  <p><code>User::with('user_role', 'user_role.name')</code></p>
  
  <p>does something like this exist? i have looked around and don't seem to find something related. The performance might be better if you can filter down the returned columns</p>