根据谷歌单元测试的标准，代码覆盖率达到 90% 就可以堪称模范了。100 分是完美，90 分是卓越。我们不追求完美，但追求卓越。
According to Google's standard for unit testing, a code coverage rate of 90% can be considered exemplary. 100 points is perfect, and 90 points is outstanding. We don't strive for perfection, but we do aim for excellence.