    def _clear_cookie(self, handler, cookie_name, **kwargs):
        """Clear a cookie, handling __Host- prefix"""
        # Set-Cookie is rejected without 'secure',
        # this includes clearing cookies!
        if cookie_name.startswith("__Host-"):
            kwargs["path"] = "/"
            kwargs["secure"] = True
        return handler.clear_cookie(cookie_name, **kwargs)
Clear a cookie, handling __Host- prefix
jupyterhub/services/auth.py