title: Sprite Kit iOS7 - SKNode UserData property not storing values
body: <p>I would think this work work easily, however I cannot understand why my NSMutableDictionary property is not working as I would have expected.</p>
  
  <pre><code>[self.testSprite.userData setValue:@"CAT" forKey:@"key"];
  NSLog(@"%@", [self.testSprite.userData objectForKey:@"key"]);
  NSLog(@"%lu", [self.testSprite.userData count]);
  </code></pre>
  
  <p>I am retuning (null) and 0.</p>
  
  <p>Is there a special trick for using the spriteNode userdata ?</p>
  
  <p>Thanks</p>