>>>
Iterable<Task> generate() sync* {
  int i = 0;

  while (i++ < 100) {
    yield new Task(i, rnd.nextInt(100), calc);
  }
}
<<<
Iterable<Task> generate() sync* {
  int i = 0;

  while (i++ < 100) {
    yield new Task(i, rnd.nextInt(100), calc);
  }
}