10.从从容容、游刃有余，匆匆忙忙、连滚带爬
decisions and operations.
，这一点在同城约会中也有详细论述
posToTime.set(pos, time);
If the transform's transform() operation is synchronous and always enqueues output immediately, it never signals backpressure back to the writable side even when the downstream consumer is slow. This is a consequence of the spec design that many developers completely overlook. In browsers, where there's only a single user and typically only a small number of stream pipelines active at any given time, this type of foot gun is often of no consequence, but it has a major impact on server-side or edge performance in runtimes that serve thousands of concurrent requests.