code: def lock_offline(self, comment=None):
          
          self.make_request(
              NodeCommandFailed,
              method='update',
              resource='lock_offline',
              params={'comment': comment})
docs: Executes a Lock-Offline operation on the specified node
          Bring back online by running :func:`go_online`.
  
          :param str comment: comment for audit
          :raises NodeCommandFailed: lock offline failed
          :return: None