title: Accessor that returns value vs accessor that returns reference?
body: <p>From my understanding both of the following getter methods reference the actual object.
  So what is the difference between the two?<br>
  When and why would you want to use the second getter method?</p>
  
  <pre><code>- (MyObject *)myObject
  {
     return _myObject;
  }
  
  - (void)getMyObject:(MyObject **)myObject
  {
     if (!myObject)
     {
        *myObject = _myObject;
     }
  }
  </code></pre>