title: Returning an NSManagedObject
body: <p>I'm running my app through instruments Allocations tools. Taking snapshots and comparing what memory is being stranded. </p>
  
  <p>Occasionally I find references to this method:</p>
  
  <pre><code>-(Book *) getBook {    
      return (Book *)[[AppDelegate getCoreDataContext] existingObjectWithID: book_id error:nil];
  }
  </code></pre>
  
  <p>Could this cause the returned Book object to leak?</p>
  
  <p>Notes: I'm use ARC and compiling for 4.2+ iPad</p>