public IActionResult Edit(int?id)
        {
            if (id == null)
            {
                return(RedirectToAction(nameof(Authors)));
            }

            Author author = authorServices.FindAuthor(id);

            EditAuthorDTO result = new EditAuthorDTO
            {
                Id         = author.Id,
                FirstName  = author.FirstName,
                MiddleName = author.MiddleName,
                LastName   = author.LastName,
                Birthday   = author.Birthday,
                Nickname   = author.Nickname,
                Country    = authorServices.GetAuthorCountry(author)
            };

            return(View(result));
        }