     
     // configuration
     func nextLevel(_ nextLevel: NextLevel, didUpdateVideoConfiguration videoConfiguration: NextLevelVideoConfiguration) {
-        
     }
     
     func nextLevel(_ nextLevel: NextLevel, didUpdateAudioConfiguration audioConfiguration: NextLevelAudioConfiguration) {
-        
     }
     
     // session
     func nextLevelSessionWillStart(_ nextLevel: NextLevel) {
+        print("nextLevelSessionWillStart")
     }
     
     func nextLevelSessionDidStart(_ nextLevel: NextLevel) {
+        print("nextLevelSessionDidStart")
     }
     
     func nextLevelSessionDidStop(_ nextLevel: NextLevel) {
+        print("nextLevelSessionDidStop")
     }
     
     // device, mode, orientation

    }
    
    func nextLevelFlashActiveChanged(_ nextLevel: NextLevel) {
        
    }
    
    func nextLevelTorchActiveChanged(_ nextLevel: NextLevel) {
        
    }
    
    func nextLevelFlashAndTorchAvailabilityChanged(_ nextLevel: NextLevel) {
        
    }
    
    // zoom

    
    // video recording session
    func nextLevel(_ nextLevel: NextLevel, didSetupVideoInSession session: NextLevelSession) {
        print("video setup!")
    }
    
    func nextLevel(_ nextLevel: NextLevel, didSetupAudioInSession session: NextLevelSession) {
        print("audio setup!")
    }
    
    func nextLevel(_ nextLevel: NextLevel, didStartClipInSession session: NextLevelSession) {
