如何在uicollectionview中获取当前的cell.contentview。如何在uicollectionview单元格中添加子视图

func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
    let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "CellIdentifier", for: indexPath)
    
    // 在这里获取cell.contentView
    let contentView = cell.contentView
    
    // 添加子视图到cell.contentView
    let subview = UIView(frame: CGRect(x: 0, y: 0, width: 100, height: 100))
    contentView.addSubview(subview)
    
    return cell
}