nextString method
Implementation
String nextString(int length,
{String charset =
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"}) {
if (charset.isEmpty) {
throw Exception("Charset cannot be empty");
}
return String.fromCharCodes(Iterable.generate(
length, (_) => charset.codeUnitAt(nextInt(charset.length))));
}