而总有些类显然不可能是不变类的， 这时也要尽可能的限制它的可变性。

There are some class immutable is impossible, then try to limit the mutability of them.

youdao

上一期中使用到的其他类保持不变。

The other classes used in that column remain the same.

youdao

OVal并不是惟一可用的dbc库，事实上其DBC结构对比其他框架来说是相当有限的(例如，它未提供指定类不变式的简易方法)。

OVal isn't the only DBC library available, and in fact its DBC constructs are fairly limiting compared to other frameworks (for example, it doesn't offer an easy way to specify class invariants).

youdao