title: Adding a pointer field to a subclass of PFUser
body: <p>I'd like to add a pointer field to my PFUser subclass, managed by the PFUser subclass. Ideally, the pointer object would be available automatically on the PFUser subclass - saved and fetched when the user is saved and fetched.</p>
  
  <p>With any other PFObject subclass, I would simply add a Dynamic property and be sure to use includeKey when querying.</p>
  
  <p>However, for a PFUser subclass, I'm never actually querying. How can I force the pointer object to fetch?</p>