     internal var _identifier: String
     internal var _date: Date
     
-    internal var _duration: CMTime
+    internal var _duration: CMTime = kCMTimeZero
     internal var _clips: [NextLevelClip]
     internal var _clipFilenameCount: Int
 

        
        self._clips = []
        self._clipFilenameCount = 0
        self._duration = kCMTimeZero
     
        self._audioQueue = DispatchQueue(label: NextLevelSessionAudioQueueIdentifier)


    /// Duration of a session, the sum of all recorded clips.
    public var duration: CMTime {
        get {
            return self._duration + self._currentClipDuration
        }
    }

