package journal type nilJournal struct{} // nilj is a singleton nil journal. var nilj Journal = &nilJournal{} func NilJournal() Journal { return nilj } func (n *nilJournal) RegisterEventType(_, _ string) EventType { return EventType{} } func (n *nilJournal) AddEntry(_ EventType, _ interface{}) {} func (n *nilJournal) Close() error { return nil }