     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)


    internal var _sessionQueue: DispatchQueue
    internal var _sessionQueueKey: DispatchSpecificKey<NSObject>
    
    internal var _currentClipDuration: CMTime = kCMTimeZero
    internal var _currentClipHasAudio: Bool
    internal var _currentClipHasVideo: Bool

