code: func GetControllerDirs(cgroups map[int][]string) []string {
  	var controllers []string
  	for _, cs := range cgroups {
  		controllers = append(controllers, strings.Join(cs, ","))
  	}
  
  	return controllers
  }
docs: // GetControllerDirs takes a map with the enabled cgroup controllers grouped by
  // hierarchy and returns the directory names as they should be in
  // /sys/fs/cgroup