code: def go_online(self, comment=None):
          
          self.make_request(
              NodeCommandFailed,
              method='update',
              resource='go_online',
              params={'comment': comment})
docs: Executes a Go-Online operation on the specified node
          typically done when the node has already been forced offline
          via :func:`go_offline`
  
          :param str comment: (optional) comment to audit
          :raises NodeCommandFailed: online not available
          :return: None