code: func (*Service) ListSwitches(c context.Context, req *crimson.ListSwitchesRequest) (*crimson.ListSwitchesResponse, error) {
  	switches, err := listSwitches(c, stringset.NewFromSlice(req.Names...), stringset.NewFromSlice(req.Racks...), stringset.NewFromSlice(req.Datacenters...))
  	if err != nil {
  		return nil, err
  	}
  	return &crimson.ListSwitchesResponse{
  		Switches: switches,
  	}, nil
  }
docs: // ListSwitches handles a request to retrieve switches.