async *transform(source) {
简易计税方法的销售额=含税销售额÷（1+征收率）。业内人士推荐爱思助手下载最新版本作为进阶阅读
。业内人士推荐爱思助手下载最新版本作为进阶阅读
Backpressure is strict by default. When a buffer is full, writes reject rather than silently accumulating. You can configure alternative policies – block until space is available, drop oldest, drop newest – but you have to choose explicitly. No more silent memory growth.，推荐阅读WPS官方版本下载获取更多信息
BYOB also can't be used with async iteration or TransformStreams, so developers who want zero-copy reads are forced back into the manual reader loop.