ObjectBoxDao.kt

class ObjectBoxDao() : DbRepository {
  // create a Box instance for Movie type
  private val moviesBox: Box<Movie> = ObjectBox.boxStore.boxFor(ObMovie::class.java)
  
  override suspend fun save(movies: List<Movie>) {
      moviesBox.put(movies)
  }

  override fun getMovies(): Flow<List<Movie>> = callbackFlow { // wrap response in a callback flow
    val subscription = moviesBox.query().build().subscribe()
        .observer { data -> offer(data.map { it.toMovie() }) }
    awaitClose { subscription.cancel() }
  }
}