public Page UpdatePage(Page page)
        {
            if (page.CreationDate == default(DateTime)) {
                page.CreationDate = DateTime.Now;
            }

            page.ModificationDate = DateTime.Now;

            return this.UpdateEntity (page, this._PageRepository);
        }
        public Page CreatePage(Page page)
        {
            var result = this.CreateEntity<Page> (page, this._PageRepository);

            if (result.CreationDate == default(DateTime)) {
                result.CreationDate = DateTime.Now;
            }

            result.ModificationDate = DateTime.Now;

            result.Tags = new HashSet<string>();
            result.SeoKeywords = new HashSet<string>();

            return result;
        }