anchor.diff:      bool wakeup = false,
       bool rescheduleOnReboot = false,
     }) async {
  +    // ignore: inference_failure_on_function_return_type
       assert(callback is Function() || callback is Function(int));
       assert(id.bitLength < 32);
       final int now = DateTime.now().millisecondsSinceEpoch;
  
positive.code:       exit(-1);
      }
  
      if (closure is Function()) {
        closure();
      } else if (closure is Function(int)) {
        final int id = args[1];
        closure(id);
  
negative.code:     bool wakeup = false,
      bool rescheduleOnReboot = false,
    }) async {
      // ignore: inference_failure_on_function_return_type
      assert(callback is Function() || callback is Function(int));
      assert(id.bitLength < 32);
      final int startMillis = time.millisecondsSinceEpoch;
  