         super.layoutSubviews()
         _layoutViews()
     }
-    
 }
 
 // MARK: - UI
 
-extension TTAAssetCollectionViewCell {
+fileprivate extension TTAAssetCollectionViewCell {
     func _setupUI() {
         _createViews()
         _configViews()

    
    var asset: TTAAsset! {
        didSet {
            imageView.image = nil
            
            let identifier = asset.assetID
            assetID = identifier

    }
    
    func _configViews() {
        layer.shouldRasterize = true
        layer.rasterizationScale = UIScreen.main.scale
        layer.drawsAsynchronously = true
        layer.contents = UIImage.image(with: .defaultAssetImage, size: min(contentView.bounds.width, contentView.bounds.height)).cgImage
        imageView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
        imageView.contentMode = .scaleAspectFill
        imageView.clipsToBounds = true
