title: Fetched property and NSPredicate
body: <p>I know how to use NSPredicate with relationships but for some reason when I do the same thing with a fetched property I get: </p>
  
  <p>Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'keypath address.id not found...' where address is a fetched property.</p>
  
  <p>The code is like this: </p>
  
  <p>[NSPredicate predicateWithFormat:@"address.id == '%i'", id]</p>
  
  <p>Can you even use fetched properties with NSPredicate?</p>