BasicSample AppDatabase volatile

[squm]

https://github.com/android/architecture-components-samples/blob/1816deaa2f2f087cc16c5cd4199c7600395b9905/BasicSample/app/src/main/java/com/example/android/persistence/db/AppDatabase.java#L44

Hello, I am looking at the “Android Room with a View - Java” and they declare database instance as volatile

    // marking the instance as volatile to ensure atomic access to the variable
    private static volatile WordRoomDatabase INSTANCE;