code: def _get_topologies_with_watch(self, callback, isWatching):
      
      path = self.get_topologies_path()
      if isWatching:
        LOG.info("Adding children watch for path: " + path)
  
      # pylint: disable=unused-variable
      @self.client.ChildrenWatch(path)
      def watch_topologies(topologies):
        """ callback to watch topologies """
        callback(topologies)
  
        # Returning False will result in no future watches
        # being triggered. If isWatching is True, then
        # the future watches will be triggered.
        return isWatching
docs: Helper function to get topologies with
      a callback. The future watch is placed
      only if isWatching is True.