docs: def _update_rs_no_primary_from_member(
          sds,
          replica_set_name,
          server_description):
      """RS without known primary. Update from a non-primary's response.
  
      Pass in a dict of ServerDescriptions, current replica set name, and the
      ServerDescription we are processing.
  
      Returns (new topology type, new replica_set_name).
      """
      topology_type = TOPOLOGY_TYPE.ReplicaSetNoPrimary
      if replica_set_name is None:
          replica_set_name = server_description.replica_set_name
  
      elif replica_set_name != server_description.replica_set_name:
          sds.pop(server_description.address)
          return topology_type, replica_set_name
  
      # This isn't the primary's response, so don't remove any servers
      # it doesn't report. Only add new servers.
      for address in server_description.all_hosts:
          if address not in sds:
              sds[address] = ServerDescription(address)
  
      if (server_description.me and
              server_description.address != server_description.me):
          sds.pop(server_description.address)
  
      return topology_type, replica_set_name