Implement all 4 types of inner classes implementing the same interface

Question

Please give me the answer

Answer 1

Giving the finished answer defeats the learning process, which is the purpose of SoloLearn.
Pls edit your question - change your tag from "sololearn" to the name of the language, and the description from "Please give me the answer" to an explanation of your difficulties.

Answer 2

About the other question: pls do another post. One question per post keeps talks organized. And, please, follow the same guidelines I mentioned for this question.