第十三条 纳税人按照一般计税方法计算缴纳增值税的，因销售折让、中止或者退回而退还给购买方的增值税税额，应当从当期的销项税额中扣减；因销售折让、中止或者退回而收回的增值税税额，应当从当期的进项税额中扣减。
The tee() memory cliff: Stream.share() requires explicit buffer configuration. You choose the highWaterMark and backpressure policy upfront: no more silent unbounded growth when consumers run at different speeds.，更多细节参见下载安装 谷歌浏览器 开启极速安全的 上网之旅。
page being returned to the operating system at n×2，详情可参考夫子
void*wrap_malloc(unsigned long long n) { return malloc(n); }