     /// If it doesn't already exist, generates a thumbnail image of the clip.
     public var thumbnailImage: UIImage? {
         get {
-            guard
-                self._thumbnailImage == nil
-            else {
+            guard self._thumbnailImage == nil else {
                 return self._thumbnailImage
             }
             

    /// Duration of the clip, otherwise invalid.
    public var duration: CMTime {
        get {
            if let asset = self.asset {
                return asset.duration
            }
            return kCMTimeZero
        }
    }
  

    /// Frame rate at which the asset was recorded.
    public var frameRate: Float {
        get {
            if let tracks = self.asset?.tracks(withMediaType: AVMediaType.video),
                tracks.isEmpty == false {
                if let videoTrack = tracks.first {
                    return videoTrack.nominalFrameRate
                }
            }
            return 0
