superclasses

Such a design would have to depend heavily on inheritance, where persistence methods would be implemented in superclasses.
这种设计严重依赖于继承，因为持久化方法要在父类中实现。
Methods that use references to superclasses must be able to use objects of subclasses without knowing it.
使用了对超类的引用的方法必须能在不知道子类具体类型的情况下使用子类对象。
It is also very easy to modify superclasses and add new subclasses because you merely need to modify or add one table.
修改超类和添加新的子类也非常容易，因为您只需要修改或添加一张表。
Another approach to the Expression Problem is multiple inheritance, in which one subclass can extend many superclasses.
表达式问题的另一种方法是多重继承，即一个子类可扩展许多超类。
This ensures that the derived classes in the unstable packages depend on the abstract superclasses and interfaces in the stable packages.
这可保证让不稳定包中的具象子类依赖于稳定包中的抽象基类和接口。
Whenever a subclass violates the existing contract between its superclasses and their clients, it forces changes in the existing code.
无论何时，只要子类违反了已经存在于其超类和它们用户之间的约定，就必然要修改现有代码。
Reducing coupling between a subclass and its superclasses.
Instance and its collection of superclasses .
ATL provides the ability to create a control that superclasses a standard Windows control.
ATL提供创建控件作为标准Windows控件的超类的能力。
This means all methods defined in the class itself, its superclasses, and any mixed in modules.
这意味着所有方法都定义在类本身、父类以及混合在模块中。