public async Task <IActionResult> AddAuthor([FromBody] AuthorResource authorResource)
        {
            try
            {
                if (!ModelState.IsValid)
                {
                    return(BadRequest(ModelState));
                }

                var author = mapper.Map <AuthorResource, Author>(authorResource);
                author.LastUpdate = DateTime.Now;
                authorsRepository.AddAuthorAsync(author);
                await unitOfWork.CompleteAsync();

                var newAuthor = await authorsRepository.GetAuthorByIdAsync(author.Id);

                return(Ok(mapper.Map <Author, AuthorResource>(newAuthor)));
            }
            catch (System.Exception ex)
            {
                return(BadRequest(ex.Message));
            }
        }