[Bit-dev] How is qt/qtsystrayicon.py invoked?

Hello folks, maybe someone can clear me up here. I need some help with an investigation. We have the file "qt/qtsystrayicon.py" in the repo containing "class QtSysTrayIcon" and also a "if __name__ == '__main__':" section. I tried to find out how this class is used but couldn't find something about it. I was using grep and also checked the Makefiles. But I also can say that on my productive system BIT does have an icon in the systray while a backup job is running. But I don't know how it gets there. Thanks for helping out. Kind Christian