code: func (g *GPG) Fingerprint(ctx context.Context, id string) string {
  	ent := g.findEntity(id)
  	if ent == nil || ent.PrimaryKey == nil {
  		return ""
  	}
  	return fmt.Sprintf("%x", ent.PrimaryKey.Fingerprint)
  }
docs: // Fingerprint returns the full-length native fingerprint