Can you give an example of using a structure from the Swift standard library?

An example of using Stream in Dart:

Stream<int> countStream(int to) async* {
  for (int i = 1; i <= to; i++) {
    await Future.delayed(Duration(seconds: 1));
    yield i; // send the next value to the stream
  }
}

void main() {
  countStream(3).listen((value) {
    print('Received value: $value');
  });
}