如果衍生类别未提供替代执行个体，则这个方法应该呼叫基底实作。

If the derived class does not provide a substitute instance, this method should call the base implementation.

youdao

如果衍生类别未提供替代执行个体，则这个方法应该呼叫基底实作。

If the derived class does not provide a substitute instance, this method should call the base implementation.

youdao