; → PLA result takes effect NOW
goes to zero it can be returned to the operating system
，详情可参考快连下载安装
When we run timeTravel(checkoutFlow, traceLog), it will actually exercise our checkout workflow, and produce the following output. With that, we’ve successfully executed a production execution trace locally, all without touching any database or external service:
为什么需要非线性？ 想象一下，如果网络里每一层都是线性的（比如 y=Wx+b），无论堆叠多少层，最终网络都只是一条线性映射。深度堆叠就没有意义了，网络的表达能力非常有限。