public static string ExportSongsAboveDuration(MusicHubDbContext context, int duration)
        {
            var songs = context.Songs
                .Where(d => d.Duration.TotalSeconds > duration)
                .Select(x => new ExportSongDto
                {
                    SongName = x.Name,
                    Writer = x.Writer.Name,
                    Performer = x.SongPerformers.Select(p => p.Performer.FirstName + " " + p.Performer.LastName).FirstOrDefault(),
                    AlbumProducer = x.Album.Producer.Name,
                    Duration = x.Duration.ToString("c")
                })
                .OrderBy(x => x.SongName)
                .ThenBy(w => w.Writer)
                .ToArray();

            var xmlSerializer = new XmlSerializer(typeof(ExportSongDto[]), new XmlRootAttribute("Songs"));

            var sb = new StringBuilder();

            var namespaces = new XmlSerializerNamespaces(new[]
            {
                XmlQualifiedName.Empty
            });
            xmlSerializer.Serialize(new StringWriter(sb), songs, namespaces);

            return sb.ToString().TrimEnd();
        }