notifyN method
Implementation
void notifyN(int n) {
if (_closed || n <= 0) return;
_epoch += n;
var count = n;
while (count > 0 && _waiters.isNotEmpty) {
final c = _waiters.removeAt(0);
if (!c.isCompleted) {
c.complete();
count--;
}
}
if (count > 0) {
_permits += count;
}
}