func dumpGroups(api *slack.Slack, dir string, rooms []string) []slack.Group { groups, err := api.GetGroups(false) check(err) if len(rooms) > 0 { groups = FilterGroups(groups, func(group slack.Group) bool { for _, room := range rooms { if room == group.Name { return true } } return false }) } if len(groups) == 0 { var groups []slack.Group return groups } for _, group := range groups { dumpChannel(api, dir, group.Id, group.Name, "group") } return groups }