[Ch10c] Improving Pool puzzle

public class StreamPuzzle {

  public static void main(String[] args) {

    List<Song> songs = new JukeboxData.Songs().getSongs();

    SongSearch songSearch = new SongSearch();

    songSearch.printTopFiveSongs();

    songSearch.searchForArtist("The Beatles");

    songSearch.searchForArtist("The Beach Boys");

  }

}

class SongSearch {

  private final List<Song> songs;

  public SongSearch() {

    songs = new JukeboxData.Songs().getSongs();

  }

  void printTopFiveSongs() {

    List<String> topFive = songs.stream()

                                .sorted(Comparator.comparingInt(Song::getTimesPlayed))

                                .map(song -> song.getTitle())

                                .limit(5)

                                .collect(Collectors.toList());

    System.out.println("Top 5 songs: " + topFive);

    searchForArtist(songs, "The Beatles");

    searchForArtist(songs, "The Beach Boys");

  }

  private static void searchForArtist(List<Song> songs, String artist) {

  void searchForArtist(String artist) {

    Optional<Song> result = songs.stream()

                                 .filter(song -> song.getArtist().equals(artist))

                                 .findFirst();