public IHttpActionResult addChapter(string mangaId, int chapterNumber, string chapterName)
        {
            ChapterDTO chapter = new ChapterDTO();

            chapter.chapterName   = chapterName;
            chapter.mangaId       = mangaId;
            chapter.chapterNumber = chapterNumber;

            if (!chapterService.addChapter(chapter))
            {
                return(NotFound());
            }
            else
            {
                return(Ok("Success"));
            }
        }