             return stingCell
         }
         
-        dataSource.supplementaryViewProvider = { collectionView, kind, indexPath in
+        dataSource?.supplementaryViewProvider = { collectionView, kind, indexPath in
             collectionView.dequeueReusableSupplementaryView(ofKind: kind, withReuseIdentifier: "AddStingFooter", for: indexPath)
         }
-        
-        return dataSource
     }
     
     @objc func applySnapshot() {

        guard
            show.stings.count > 1,
            let oldCue = cuedSting,
            let oldCueIndex = dataSource.indexPath(for: oldCue)?.item,
            oldCueIndex > 0
        else { return }
        

        }
    }
    
    func configureDataSource() {
        dataSource = UICollectionViewDiffableDataSource<Int, Sting>(collectionView: collectionView) { collectionView, indexPath, sting -> UICollectionViewCell? in
            let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "Sting Cell", for: indexPath)
            
            guard let stingCell = cell as? StingCell else { return cell }
