the table view cells not release from memory - swift3

Question

i hope all is well
i have an issue with cell in table view it's not releasing when i scrolling in table view the following is my code
class MovieDownloadedTableViewCell: UITableViewCell {
#IBOutlet weak var movieImageView: UIImageView!
#IBOutlet weak var movieNameLabel: UILabel!
#IBOutlet weak var movieEmptyCircleImageView: UIImageView!
#IBOutlet weak var movieCheckMarkImageView: UIImageView!
var fetchURL:URL? {
didSet {
updateUI()
}
}
func updateUI() {
movieImageView.image = nil
movieNameLabel.text = nil
movieEmptyCircleImageView.isHidden = true
movieCheckMarkImageView.isHidden = true
if let fetchURL = fetchURL {
if fetchURL.pathExtension == "" {
movieImageView.image = UIImage(named: "folder")
}else{
movieImageView.image = UIImage(named: "movie")
}
movieNameLabel.text = fetchURL.lastPathComponent
}// end the if let
}// end the func updateUI
}// end the class
the above my custom table view cell
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "Cell") as? MovieDownloadedTableViewCell
// defining the cell
if let cell = cell {
cell.tintColor = UIColor.white
cell.fetchURL = operationDocumentDirectoryObject.arrayOfMovieURL?[indexPath.row]
if isShowToolBar {
if operationDocumentDirectoryObject?.arrayOfShowAllEmptyCircle?[indexPath.row] == indexPath.row {
cell.movieEmptyCircleImageView.isHidden = false
}// end the if
if operationDocumentDirectoryObject.dictionaryHoldIndexCellForDisplayWhichCellSelected.count > 0 {
if operationDocumentDirectoryObject.dictionaryHoldIndexCellForDisplayWhichCellSelected[indexPath.row] == indexPath.row {
cell.movieEmptyCircleImageView.isHidden = true
cell.movieCheckMarkImageView.isHidden = false
}
}
}// end if for the isShowVar
}// end the creating cell
return cell!
}
please where my wrong code how can i make my table view cell when i scrolling is releasing from memory every time
thank you very much