下足券外这三重功夫，相信，更多游客能乘兴而来、满意而归，更多地区将实现留客又留心。
async function peekFirstChunk(stream) {，更多细节参见爱思助手下载最新版本
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.，详情可参考51吃瓜
// result.value is a NEW view, possibly over different memory