Many, if not most Android apps act as API clients thus require conversion between data-interchange format (usually JSON) and POJO (data model classes). There is no need to implement conversion engine in our code since it can done by external libraries like GSON or moshi. It may be useful to test parsing (JSON to POJO) and generating (POJO to JSON) logic related to model classes.

Project link: https://www.thedroidsonroids.com/blog/unit-tests-rules-annotations-resources