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)
def do_register_opts(opts, group=None, ignore_errors=False):
    try:
        cfg.CONF.register_opts(opts, group=group)
    except:
        if not ignore_errors:
            raise