     /// The exposure mode of the device.
     public var exposureMode: NextLevelExposureMode {
         get {
-            if let device: AVCaptureDevice = self._currentDevice {
+            if let device = self._currentDevice {
                 return device.exposureMode
             }
             return .locked
         }
         set {
-            guard let device: AVCaptureDevice = self._currentDevice,
+            guard let device = self._currentDevice,
                 device.exposureMode != newValue,
                 device.isExposureModeSupported(newValue)
                 else {

        else {
            return
        }
            
        do {
            try device.lockForConfiguration()
            
            device.setExposureTargetBias(targetBias, completionHandler: nil)
            
            device.unlockForConfiguration()
        } catch {
            print("NextLevel, setExposureModeCustom failed to lock device for configuration")
        }
    }
    

            return
        }
 
        let newISO = iso.clamped(to: device.activeFormat.minISO...device.activeFormat.maxISO)
        
        do {
            try device.lockForConfiguration()
            
            device.setExposureModeCustom(duration: AVCaptureDevice.currentExposureDuration, iso: newISO, completionHandler: nil)
            
            device.unlockForConfiguration()
        } catch {
