learningfunctional-3.7.kt

fun albumAndTrackLowerThanGivenSeconds_v2(durationInSeconds: Int, albums: List<Album>): List<Pair<String, String>> {
    return albums.flatMap {
        val album = it.title
        it.tracks.filter {
            it.durationInSeconds <= durationInSeconds
        }.map {
            Pair(album, it.title)
        }
    }
}