def save(self, filename=None):
        filename = Path(filename) if filename is not None else self.filename
        with filename.open("w") as f:
            f.write(self.yaml)
async def print_debug(loop):
    while True:
        print(chr(27) + "[2J")  # clear screen
        loop.print_debug_info()
        await asyncio.sleep(0.5)