Comments by snp_shailesh (Top 2 by date)

Thanks for reply .
I am agree with your explaination.
But still have some generic questions.

As the AbstractSet implements/overrides some methods of Set interface, the same set of methods will be available for its subclass too .
So our HashSet(which extends AbstractSet) can directely overrides its superclass methods in its own featured way .
But instead, HashSet still implements "Set" interface to override the methods. My doubt is, why java has allowed such redundant implementation of interfaces ?