   
   /**
    Create `audioInput` and add it to `captureSession`.
-   - Throws: `CaptureManagerError.InvalidCaptureInput` if the input cannot be added to `captureSession`.
+   - Throws: `CaptureManagerError.invalidCaptureInput` if the input cannot be added to `captureSession`.
   */
   fileprivate func addAudioInput() throws {
     let audioDevice = AVCaptureDevice.defaultDevice(withMediaType: AVMediaTypeAudio)

   - parameter outputs: A mask of options of type `CaptureSessionOutputs` indicating what outputs to add to the `AVCaptureSession`.
   - parameter errorHandler: A closure of type `(Error) -> Void`. Called on the **main thread** if anything performed inside of `sessionQueue` thread throws an error.
   
   - Throws: `CaptureManagerError.InvalidSessionPreset` if `sessionPreset` is not valid.
   */
  public func setUp(sessionPreset: String,
                  previewLayerProvider: VideoPreviewLayerProvider?,

  
  /**
   Set the sessionPreset for the AVCaptureSession.
   - Throws: `CaptureManager.invalidSessionPresent` if `sessionPreset` is not valid.
   */
  fileprivate func setSessionPreset(_ preset: String) throws {
    if !captureSession.canSetSessionPreset(preset) {
