问带有来自API的图像的Swift tableView在滚动时滞后

EN

  override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCell(withIdentifier: "VideoCell", for: indexPath) as! TableViewCell
    let video = highlightsArray[indexPath.row]
    cell.video = video

    do {

        let url = URL(string: self.highlightsArray[indexPath.row].thumbnail)!
        let data = try Data(contentsOf: url)
        cell.thumbnailImage.image = UIImage(data: data)
    }
    catch{
        print(error)
        cell.thumbnailImage.image = UIImage(named: "pllogo.jpg")
    }


    return cell
}