public async Task <ActionResult> Update(int id, [FromBody] BookRequest bookModel)
        {
            if (id != bookModel.Id)
            {
                return(BadRequest());
            }
            var book = _mapper.Map <Book>(bookModel);

            try
            {
                await _bookRepository.Update(book);
            }
            catch (DbUpdateConcurrencyException)
            {
                if (!_bookRepository.BookExists(book.Id))
                {
                    return(NotFound());
                }
            }
            return(NoContent());
        }