每一件货的下面都有一个按钮，而我们看到的货，其实都是样品，而我们买到的不是这些样品，而是放在自动售货机的里面的仓库里面，当我们按动按钮时，这时与这件货相对应的仓库门就会打开了，这时，我们就会受到我们想要的货了!-Every piece of cargo below has a button, and we can see the goods, in fact, are samples, and we do not buy these samples, but on the inside the

This book is primarily for software developers. I assume you have a basic understanding of Internet technologies and programming techniques. Code samples are scattered throughout the text and are provided in numerous languages, so fluency in lang