pub type UICollectionViewDiffableDataSourceSupplementaryViewProvider = *mut DynBlock<dyn Fn(NonNull<UICollectionView>, NonNull<NSString>, NonNull<NSIndexPath>) -> *mut UICollectionReusableView>;Available on crate features
UICollectionView and UICollectionViewCell and UIDiffableDataSource and UIResponder and UIScrollView and UIView and block2 only.