isUUID function
check if the string is a UUID (version 3, 4 or 5).
Implementation
bool isUUID(String? str, [version]) {
if (version == null) {
version = 'all';
} else {
version = version.toString();
}
RegExp? pat = _uuid[version];
return (pat != null && pat.hasMatch(str!.toUpperCase()));
}