I didn't intend to prove that. Programming is not mathematics, there is nothing that can be proved there. But there are good and bad practices. I showed why generally implementation inheritance is bad.
In order to fix Hadoop's inheritance issues I should realize what it is about internally, and I don't. Anyway, do you think that it's just impossible to replace inheritance with composition? And who told you that Hadoop is a top-quality project?
I didn't intend to prove that. Programming is not mathematics, there is nothing that can be proved there. But there are good and bad practices. I showed why generally implementation inheritance is bad.
In order to fix Hadoop's inheritance issues I should realize what it is about internally, and I don't. Anyway, do you think that it's just impossible to replace inheritance with composition? And who told you that Hadoop is a top-quality project?
Here is how a world without (almost) any inheritance could look like: github.com/yegor256/takes