ReactiveCocoa-How can i avoid to multiple subscribe the signal in collectionView's cell
<pre><code>func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -&gt; UICollectionViewCell {
    let cell = collectionView.dequeueReusableCellWithReuseIdentifier(identifier, forIndexPath: indexPath) as! ComposeCell
    cell.deletePictureSignal.subscribeNext { (response) -&gt; Void in
        print("delete picture")
        let deleteIndex = (self.pictureView.indexPathForCell(cell)?.item)!
        self.pictures.removeAtIndex(deleteIndex)
        //            self.pictureView.reloadData()
    }
    cell.addPictureSignal.subscribeNext { (response) -&gt; Void in
        print("add picture")
        self.selectedIndex = (self.pictureView.indexPathForCell(cell)?.item)!
        let imagePicker = UIImagePickerController()
        imagePicker.delegate = self
        self.presentViewController(imagePicker, animated: true, completion: nil)
    }
   return cell
}
</code></pre>

<p>when I reloadData,this way will be implemented again,and Signal will be subscribe many time,how can I resolve it and ensure subscribe only once?</p>