code: def _update(self, rules: list):
          
          self._rules = rules
          to_store = '\n'.join(
              rule.config_string
              for rule in rules
          )
          sftp_connection = self._sftp_connection
          with sftp_connection.open(self.RULE_PATH, mode='w') as file_handle:
              file_handle.write(to_store)
docs: Updates the given rules and stores
          them on the router.