docs: def keys(self):
          """Get the keys associated with this lease.
  
          :return:
          """
          result = self.client.post(self.client.get_url("/kv/lease/timetolive"),
                                    json={"ID": self.id,
                                          "keys": True})
          keys = result['keys'] if 'keys' in result else []
          return [_decode(key) for key in keys]