Is it meaningless code? [File: stream.cc]

[yy-tayu]

Hi,
In the file stream.cc, I found several strange codes as follows：

LocalStream::LocalStream(const LocalCameraStreamParameters& parameters,
                         int& error_code) {
    //do something...
    **rtc::scoped_refptr<webrtc::VideoCaptureModule> capturer(nullptr);**
    //do something...
}

LocalStream::LocalStream(
    std::shared_ptr<LocalDesktopStreamParameters> parameters,
    std::unique_ptr<LocalScreenStreamObserver> observer) {
    //do something...
    **std::unique_ptr<BasicDesktopCapturer> capturer(nullptr);**
    //do something...
}

LocalStream::LocalStream(
    std::shared_ptr<LocalCustomizedStreamParameters> parameters,
    std::unique_ptr<VideoFrameGeneratorInterface> framer) {
    //do something...
  **std::unique_ptr<CustomizedFramesCapturer> capturer(nullptr);**
    //do something...
}

LocalStream::LocalStream(
    std::shared_ptr<LocalCustomizedStreamParameters> parameters,
    VideoEncoderInterface* encoder) {
    //do something...
    **std::unique_ptr<CustomizedFramesCapturer> capturer(nullptr);**
    //do something...
}

Why?
Thanks in advance!