Perhaps you need the source code and don't have it (as may be the case with a commercial class library). Or maybe any change would require modifying lots of existing subclasses.

可能需要源代码，而你却不能得到它或者任何的改变需要改变很多存在的子类。

youdao

The results indicated that, along with application of normal fertilizers, application of sludge organic fertilizer could significantly increase potato yield, commercial class and quality.

结果表明，在施化肥的基础上，施用污泥有机肥可显著提高马铃薯产量、等级和品质；

youdao

What this does is it increases the role of this commercial middle class.

这点就增强了中产阶级，在商业中发挥的作用。

youdao

What this does is it increases the role of this commercial middle class.

这点就增强了中产阶级,在商业中发挥的作用

耶鲁公开课 - 欧洲文明课程节选

One can see that this was once a vibrant city with an active commercial class.

FORBES: We've Seen This Movie Before

The tone seems stuck at a lazy bonhomie, amusement for a rising, self-satisfied commercial class.

NEWYORKER: Haarlem Shuffle

Most major commercial real-estate markets classify commercial buildings as Class A, B and C buildings.

FORBES: Green Buildings: Bonafide Buzz or Balderdash?