docs: def filter_unmanaged_physnets(query):
      """Filter ports managed by other ML2 plugins """
      config = cfg.CONF.ml2_arista
      managed_physnets = config['managed_physnets']
  
      # Filter out ports bound to segments on physnets that we're not
      # managing
      segment_model = segment_models.NetworkSegment
      if managed_physnets:
          query = (query
                   .join_if_necessary(segment_model)
                   .filter(segment_model.physical_network.in_(
                       managed_physnets)))
      return query