code: func (cgroupName CgroupName) ToSystemd() string {
  	if len(cgroupName) == 0 || (len(cgroupName) == 1 && cgroupName[0] == "") {
  		return "/"
  	}
  	newparts := []string{}
  	for _, part := range cgroupName {
  		part = escapeSystemdCgroupName(part)
  		newparts = append(newparts, part)
  	}
  
  	result, err := cgroupsystemd.ExpandSlice(strings.Join(newparts, "-") + systemdSuffix)
  	if err != nil {
  		// Should never happen...
  		panic(fmt.Errorf("error converting cgroup name [%v] to systemd format: %v", cgroupName, err))
  	}
  	return result
  }
docs: // cgroupName.ToSystemd converts the internal cgroup name to a systemd name.
  // For example, the name {"kubepods", "burstable", "pod1234-abcd-5678-efgh"} becomes
  // "/kubepods.slice/kubepods-burstable.slice/kubepods-burstable-pod1234_abcd_5678_efgh.slice"
  // This function always expands the systemd name into the cgroupfs form. If only
  // the last part is needed, use path.Base(...) on it to discard the rest.