Wait: block until space becomes available
В Финляндии предупредили об опасном шаге ЕС против России09:28，更多细节参见91视频
// And the reader is no longer available when we return，这一点在im钱包官方下载中也有详细论述
Even this relatively clean version requires: a TransformStream, manual TextEncoder and TextDecoder, and explicit lock release.