code: func NewDCESecurity(domain Domain, id uint32) (UUID, error) {
  	uuid, err := NewUUID()
  	if err == nil {
  		uuid[6] = (uuid[6] & 0x0f) | 0x20 // Version 2
  		uuid[9] = byte(domain)
  		binary.BigEndian.PutUint32(uuid[0:], id)
  	}
  	return uuid, err
  }
docs: // NewDCESecurity returns a DCE Security (Version 2) UUID.
  //
  // The domain should be one of Person, Group or Org.
  // On a POSIX system the id should be the users UID for the Person
  // domain and the users GID for the Group.  The meaning of id for
  // the domain Org or on non-POSIX systems is site defined.
  //
  // For a given domain/id pair the same token may be returned for up to
  // 7 minutes and 10 seconds.