public async Task <IActionResult> VoteComment(int ratingID, int bookID)
        {
            //Gets Current User.
            var user = await _userManager.GetUserAsync(User);

            var userID = user.Id;

            //Adds vote to Rating.
            _ratingService.AddVote(userID, ratingID);
            //Redirects user to same page after voting.
            return(RedirectToAction("Details", "Book", new { id = bookID }));
        }