dsn.go
func GenOpaque(u *URL) (string, error) {
	if u.Opaque == "" {
		return "", ErrMissingPath
	}

	return u.Opaque + genQueryOptions(u.Query()), nil
}
func GenOpaque(u *URL) (string, error) {
	if u.Opaque == "" {
		return "", ErrMissingPath
	}

	return u.Opaque + genQueryOptions(u.Query()), nil
}
// GenOpaque generates a opaque file path DSN from the passed URL.