Next time the generator is called, it picks up where it left before -- both in terms of function flow and in terms of variable values.
下次调用生成器时，它再接着上次的位置 — 包括函数流和变量值这两个方面。
2
As you can see the type of the class variables is generic, but you can improve the generator to understand if a variable should contain a number or a function.