package guestbook import ( "errors" "time" ) type Reply struct { ID int64 `json:"id,omitempty"` Created string `json:"created,omitempty"` Message string `json:"message"` } func NewReply(entryID int64, message string) (*Reply, error) { if message == "" { return nil, errors.New("empty reply field") } return &Reply{ ID: entryID, Created: time.Now().UTC().Format(DateFormat), Message: message}, nil }