Classes can be nested in other classes. Enums provide an elegant notation for a limited set of constant values

Objects, Singletons & Companion objects

A class can implement an interface Base by delegating all of its public members to a specified object

AndroidX is the open-source project that the Android team uses to develop, test, package, version and release libraries within Jetpack

A simple set of rules and requirements that dictate how version numbers are assigned and incremented

Migrate to AndroidX + manage library versions more optimally

The Room persistence library provides an abstraction layer over SQLite

Implementation of PlacemarkStoreRoom, which stores placemarks in a SQLite database

Introduce a new PlacemarkStore implementation to persist to an SQLite database