title: How to find all keys used in NSKeyedArchiver/NSKeyedUnarchiver
body: <p>I have an NSData that was created by using <code>NSKeyedArchiver</code>. Is there a way to iterate over all the values inside it? It must somehow be possible to get all the keys that were stored in it when using <code>+[NSKeyedUnarchiver unarchiveObjectWithData:]</code>.</p>
  
  <p>Thanks</p>