    def clear_oauth_state_cookies(self, handler):
        """Clear persisted oauth state"""
        for cookie_name, cookie in handler.request.cookies.items():
            if cookie_name.startswith(self.state_cookie_name):
                self._clear_cookie(
                    handler,
                    cookie_name,
                    path=self.cookie_path,
                )
Clear persisted oauth state
jupyterhub/services/auth.py