public ActionResult Accept(int friendId)
        {
            var user   = _userManager.GetByEmail(User.Identity.Name);
            var friend = _friendManager.GetReceivedFriendById(friendId, user.Id);

            friend.IsAccepted = true;
            _friendManager.AcceptFriend(friend);
            return(RedirectToAction("ReceivedRequests"));
        }