public static IEnumerable <RelationComposerTrack> GetRelationsComposerTrack(ArtistWithTracks artistWithTracks)
 {
     foreach (var track in artistWithTracks.Tracks)
     {
         if (track.IsComposer)
         {
             yield return(new RelationComposerTrack
             {
                 ArtistId = artistWithTracks.ArtistId, TrackId = track.TrackId
             });
         }
     }
 }
 public static IEnumerable <RelationArtistTrack> GetRelationsArtistTrack(ArtistWithTracks artistWithTracks)
 {
     foreach (var track in artistWithTracks.Tracks)
     {
         if (!track.IsComposer && !track.IsFeatured)
         {
             yield return(new RelationArtistTrack
             {
                 ArtistId = artistWithTracks.ArtistId, TrackId = track.TrackId, Year = track.Year
             });
         }
     }
 }