resource

resource 是一个对象，表示已初始化的实际异步资源。 访问对象的 API 可能由资源的创建者指定。 Node.js 本身创建的资源是内部的，可能随时更改。 因此没有为这些指定 API。

在某些情况下，出于性能原因，资源对象会被重用，因此将其用作 WeakMap 中的键或向其添加属性是不安全的。

resource is an object that represents the actual async resource that has been initialized. The API to access the object may be specified by the creator of the resource. Resources created by Node.js itself are internal and may change at any time. Therefore no API is specified for these.

In some cases the resource object is reused for performance reasons, it is thus not safe to use it as a key in a WeakMap or add properties to it.