randomString function
Implementation
String randomString(int len) {
final random = Random();
const chars = 'AaBbCcDdEeFfGgHhIiJjKkLlMmNnOoPpQqRrSsTtUuVvWwXxYyZz1234567890';
return List.generate(len, (index) => chars[random.nextInt(chars.length)]).join();
}