title: Single model update for multiple changes in NSArrayController subclass
body: <p>I implemented an <code>NSArrayController</code> subclass to implement row reordering with bindings, using the code included in <a href="http://www.red-sweater.com/blog/274/a-moveable-beast" rel="nofollow">this post</a> as a starting point. In the <code>-tableView:acceptDrop:row:dropOperation:</code> method, I perform the following:</p>
  
  <pre><code>[self removeObjectAtArrangedObjectIndex:removeIndex];
  [self insertObject:object atArrangedObjectIndex:insertIndex];
  </code></pre>
  
  <p>The above code updates the model twice (one for each statement). 
  For my purposes, I would like to have only one update. </p>
  
  <p>Is there any way to achieve this?</p>
  
  <p>Thanks.</p>