internal static IEnumerable <MasterFile> ExtractFilesFromFolder(string directory)
 {
     foreach (var path in Directory.EnumerateFiles(directory))
     {
         if (IsMediaFile(path))
         {
             yield return(MasterFile.GetMasterFileFromFilepath(path));
         }
     }
 }
        private static void ExtractFiles(string directory)
        {
            var filesInFolder = Directory.EnumerateFiles(directory, "", SearchOption.AllDirectories);

            foreach (var path in Directory.EnumerateFiles(directory))
            {
                if (IsMediaFile(path))
                {
                    files.Add(MasterFile.GetMasterFileFromFilepath(path));
                }
            }

            foreach (var subdirectory in Directory.EnumerateDirectories(directory))
            {
                ExtractFiles(subdirectory);
            }
        }