public void SaveDownloadedChapter(IChapterRecord chapter, DirectoryInfo downloadedFiles, string outputFolder, out string path)
{
if (chapter == null)
throw new ArgumentNullException("chapter");
if (downloadedFiles == null)
throw new ArgumentNullException("downloadedFiles");
if (String.IsNullOrEmpty(outputFolder))
throw new ArgumentException("Output path must not be null or empty.", "outputFolder");
var outputDir = new DirectoryInfo(Path.Combine(outputFolder, GetNameForSave(chapter)));
path = outputDir.FullName;
DirectoryCopy(downloadedFiles.FullName, path, true);
}