code: func NewUUID() UUID {
  	gu, err := guuid.NewUUID()
  	if err == nil {
  		return UUID(gu[:])
  	}
  	return nil
  }
docs: // NewUUID returns a Version 1 UUID based on the current NodeID and clock
  // sequence, and the current time.  If the NodeID has not been set by SetNodeID
  // or SetNodeInterface then it will be set automatically.  If the NodeID cannot
  // be set NewUUID returns nil.  If clock sequence has not been set by
  // SetClockSequence then it will be set automatically.  If GetTime fails to
  // return the current NewUUID returns nil.