appdb kotlin

@Database(entities = arrayOf(Movie::class), version = 1, exportSchema = false)
public abstract class AppDb : RoomDatabase() {
//    abstract fun

    companion object {
        @Volatile
        private var instance: AppDb? = null

        fun getInstance(context:Context): AppDb {
            val tempInstance = instance

            if (tempInstance != null){
                return tempInstance
            }

            synchronized(this) {
                val instanceSyn = Room.databaseBuilder(
                    context.applicationContext,
                    AppDb::class.java,
                    "movie_database_kotlin"
                ).build()
                instance = instanceSyn
                return  instanceSyn
            }
        }
    }
}