exec method
Implementation
({Map<String, String> pathname})? exec(Uri url) {
final match = _re.firstMatch(url.path);
if (match == null) return null;
final params = <String, String>{};
for (final name in _names) {
final value = match.namedGroup('_$name');
if (value != null) params[name] = value;
}
return (pathname: params);
}