public static ArrayList<Media> insertAlphabeticalAlbum(ArrayList<Media> mediaList) {
        ArrayList<Media> result = new ArrayList<>();
        String begin = "";
        for (Media media : mediaList) {
            if (media.getMusic().getAlbum() != null) {
                if (!media.getMusic().getAlbum().substring(0, 1).toUpperCase().equals(begin)) {
                    begin = media.getMusic().getAlbum().substring(0, 1).toUpperCase();
                    result.add(new Media(begin));
                }
            } else {
                if (!begin.equals("Unknown")) {
                    begin = "Unknown";
                    result.add(new Media(begin));
                }
            }
            result.add(media);
        }
        return result;
    }

    public static ArrayList<Media> insertAlphabeticalGenre(ArrayList<Media> mediaList) {
        ArrayList<Media> result = new ArrayList<>();
        String begin = "";
        for (Media media : mediaList) {
            if (media.getMusic().getGenre() != null) {
                if (media.getMusic().getGenre().substring(0, 1).toUpperCase().equals(begin)) {
                    begin = media.getMusic().getGenre().substring(0, 1).toUpperCase();
                    result.add(new Media(begin));
                }
            } else {
                if (!begin.equals("Unknown")) {
                    begin = "Unknown";
                    result.add(new Media(begin));
                }
            }
            result.add(media);
        }
        return result;