title: performSelector:withObject:afterDelay: within NSOperation
body: <p>I'm executing some code within some <code>NSOperation</code> objects managed by an <code>NSOperationQueue</code>. The code also contains a delayed method call using <code>performSelector:withObject:afterDelay:</code>.</p>
  
  <p>The problem is, that the corresponding selector which <em>should</em> be called delayed, is <strong>not called at all</strong>.</p>
  
  <p>Having read <a href="https://stackoverflow.com/a/7277907/354018">this answer to a StackOverflow question</a>, I guess it's due to the fact that the <code>NSOperation</code> already has finished and its thread doesn't even exist anymore, "forgetting" the scheduled call to the selector.</p>
  
  <p>How can I work around this?
  <strong>How can I do a delayed call to a method within an <code>NSOperation</code>?</strong></p>