             let lastTimestamp = presentationTimestamp + duration
             
             self._audioQueue.async {
-                if let audioInput = self._audioInput {
-                    if audioInput.isReadyForMoreMediaData && audioInput.append(adjustedBuffer) {
-                        self._lastAudioTimestamp = lastTimestamp
-                        
-                        if !self.currentClipHasVideo {
-                            self._currentClipDuration = lastTimestamp - self._startTimestamp
-                        }
-                        
-                        self._currentClipHasAudio = true
-                        
-                        completionHandler(true)
-                        return
-                    }
+                if let audioInput = self._audioInput,
+                    audioInput.isReadyForMoreMediaData && audioInput.append(adjustedBuffer) {
+                    self._lastAudioTimestamp = lastTimestamp
+                    
+                    if !self.currentClipHasVideo {
+                        self._currentClipDuration = lastTimestamp - self._startTimestamp
+                    }
+                    
+                    self._currentClipHasAudio = true
+                    
+                    completionHandler(true)
+                    return
                 }
                 completionHandler(false)
             }

    /// - Parameter removeFiles: When true, associated files are also removed.
    public func removeAllClips(removeFiles: Bool = true) {
        self.executeClosureAsyncOnSessionQueueIfNecessary {
            while self._clips.count > 0 {
                if let clipToRemove = self._clips.first {
                    if removeFiles {
                        clipToRemove.removeFile()

    public var lastClipUrl: URL? {
        get {
            var lastClipUrl: URL? = nil
            if !self._clips.isEmpty,
                let lastClip: NextLevelClip = self.clips.last,
                let clipURL = lastClip.url {
                lastClipUrl = clipURL
            }
            return lastClipUrl
        }
