Applying new snapshot to diffable data source in iOS 15 trigger unnecessary cell registration call

The definition of ITEM list below, could you see  any problem here? @J0hn

class AlbumItem: Hashable {
  let albumURL: URL
  let albumTitle: String
  let imageItems: [AlbumDetailItem]
  init(albumURL: URL, imageItems: [AlbumDetailItem] = []) {
    self.albumURL = albumURL
    self.albumTitle = albumURL.lastPathComponent.displayNicely
    self.imageItems = imageItems
  }

  func hash(into hasher: inout Hasher) {
    hasher.combine(identifier)
  }

  static func == (lhs: AlbumItem, rhs: AlbumItem) -> Bool {
    return lhs.identifier == rhs.identifier
  }

  private let identifier = UUID()
}

BTW, those unnecessary calling  occurs in  demo on session 10252，to reproduce this issue:

1. add delegate for the collection view, disable prefetching to reduce logs:

  private func configureHierarchy() {
        collectionView = UICollectionView(frame: view.bounds, collectionViewLayout: createLayout())
        collectionView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
        collectionView.backgroundColor = .systemBackground
//        collectionView.prefetchDataSource = self
        collectionView.isPrefetchingEnabled = false
        collectionView.delegate = self
        view.addSubview(collectionView)
    }

2.  implement the selection callback for removing item from snapshot:

extension PostGridViewController: UICollectionViewDelegate {
    func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
        print("remove items at section:(\(indexPath.section)), item:(\(indexPath.item))")
        var snapshot = dataSource.snapshot()
        let identfiers = snapshot.itemIdentifiers(inSection: Section.ID.allCases[indexPath.section])
        snapshot.deleteItems([identfiers[indexPath.item]])
        dataSource.apply(snapshot, animatingDifferences: false)
    }
}

1. finally, remove reload stuff in cell registeration:

 let cellRegistration = UICollectionView.CellRegistration<DestinationPostCell, DestinationPost.ID> { [weak self] cell, indexPath, postID in
            guard let self = self else { return }
            print("configure DestinationPostCell:(\(Unmanaged.passUnretained(cell).toOpaque())) at section:(\(indexPath.section)), item:(\(indexPath.item))")
            let post = self.postsStore.fetchByID(postID)
            let asset = self.assetsStore.fetchByID(post.assetID)
            cell.configureFor(post, using: asset)
        }

THEN I ran this demo and clicked the first item to remove it, similar log came out:

configure DestinationPostCell:(0x000000015ef11940) at section:(0), item:(0)
configure DestinationPostCell:(0x000000015ed20410) at section:(0), item:(1)
configure DestinationPostCell:(0x000000015ed21900) at section:(1), item:(0)
remove items at section:(0), item:(0)
configure DestinationPostCell:(0x000000015ed433c0) at section:(1), item:(2)
configure DestinationPostCell:(0x000000015ed433c0) at section:(0), item:(0)
configure DestinationPostCell:(0x000000015ed433c0) at section:(1), item:(0)
configure DestinationPostCell:(0x000000015ed433c0) at section:(1), item:(1)
configure DestinationPostCell:(0x000000015ef11940) at section:(1), item:(1)