An open class isn't limited to the set of methods that were implemented when it was defined.

在定义时，开放式类并不只限于一组被实现的方法。

youdao

Please describe an example of an "open class".

请描述一次公开课的例子。

youdao

Please describe an example of an "open class".

请描述一次公开课的例子。

youdao