dce.go
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
}
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
}
// 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.