randomStringWithNumber function
Implementation
String randomStringWithNumber(int length) {
var r = Random();
const _chars = 'AaBbCcDdEeFfGgHhIiJjKkLlMmNnOoPpQqRrSsTtUuVvWwXxYyZz0123456789';
var stringWithNumber =
List.generate(length, (index) => _chars[r.nextInt(_chars.length)]).join();
return stringWithNumber;
}