ExampleRoomDatabase.kt

@Database(entities = ExampleEntity::class, version = 1, exportSchema = false)
@TypeConverters(Converters::class)
abstract class AppDatabase : RoomDatabase() {
    abstract fun exampleDao(): ExampleDao

    companion object {

        // For Singleton instantiation
        @Volatile private var instance: AppDatabase? = null

        fun getInstance(context: Context): AppDatabase {
            return instance ?: synchronized(this) {
                instance ?: buildDatabase(context).also { instance = it }
            }
        }
}