title: Error when attempting to cancel a UILocalNotification
body: <p>I schedule a <code>UILocalNotification</code> from my <code>UITableViewCell</code> subclass:</p>
  
  <pre><code>UILocalNotification *notification = [[UILocalNotification alloc] init];
  
  [notification setFireDate:[NSDate dateWithTimeIntervalSinceNow:event.destinationTime]];
  
  [notification setAlertBody:title];
  [notification setTimeZone:[NSTimeZone defaultTimeZone]];
  
  [[UIApplication sharedApplication] scheduleLocalNotification:notification];
  self.eventNotification = notification; // assigning to class property
  </code></pre>
  
  <p>And I try to cancel the notification when I delete the cell:</p>
  
  <pre><code>- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath {
  
      CustomCell *cell = (CustomCell *) [self.tableView cellForRowAtIndexPath:indexPath];
  
      [[UIApplication sharedApplication] cancelLocalNotification:cell.eventNotification];
  }
  </code></pre>
  
  <p>But when I run, I get the following error when deleting the cell:</p>
  
  <p><code>'NSInvalidArgumentException', reason: '*** -[__NSPlaceholderArray initWithObjects:count:]: attempt to insert nil object from objects[0]'
  </code></p>
  
  <p>What is the problem? Or am I doing it wrong? Thanks!</p>