public BlogOperationResult Add(User entity)
        {
            if (Exists(entity))
            {
                return(BlogOperationResult.UserExists);
            }
            using (_db = new BlogEngineDbContext())
            {
                _db.Users.Add(entity);
                Added?.Invoke(this, "user-added-message", entity);
                _db.SaveChanges();
            }

            return(BlogOperationResult.OK);
        }
        public BlogOperationResult Remove(User entity)
        {
            if (!Exists(entity))
            {
                return(BlogOperationResult.UserDoesNotExist);
            }

            using (_db = new BlogEngineDbContext())
            {
                _db.Users.Remove(entity);
                Removed?.Invoke(this, "user-removed-message", entity);
                _db.SaveChanges();
            }

            return(BlogOperationResult.OK);
        }