// 优化：如果本轮没交换，说明已经有序
1. Where is the story coming from? Is it from a reputable source or news site? Some sites specialise in ‘gossip’ and rumour style stories while others focus on the facts. It’s important to know the difference between the two.
，更多细节参见91视频
The primary signal is desiredSize on the controller. It can be positive (wants data), zero (at capacity), negative (over capacity), or null (closed). Producers are supposed to check this value and stop enqueueing when it's not positive. But there's nothing enforcing this: controller.enqueue() always succeeds, even when desiredSize is deeply negative.
Дания захотела отказать в убежище украинцам призывного возраста09:44
await blocking.writer.write(chunk5); // waits until consumer reads