def on_cleanup_error(function, path, excinfo):
                click.secho("warning: failed to remove file or directory: {}\n"
                            "please delete it manually.".format(path),
                            fg="red")
def object_id(self):
        return ("ip-path-mtu-%d-%s-%d" % (self.table_id,
                                          self.nh,
                                          self.pmtu))