title: NSManagedObject as NSDictionary key?
body: <p>In my app, I have a <code>NSDictionary</code> whose keys should be instances of a subclass of <code>NSManagedObject</code>. </p>
  
  <p>The problem, however, is that <code>NSManagedObject</code> does not implement the <code>NSCopying</code> protocol which means that no Core Data objects / instances of <code>NSManagedObject</code> can be used as dictionary keys even though the <code>-[hash]</code> method works fine for them.</p>
  
  <p>Was should I do?</p>