public static IHtmlContent ShowCreateDropDown <TPage, TEnum>(this IHtmlHelper <TPage> h,
                                                                     IButtonForCreateDropDown <TPage, TEnum> page)
        {
            var s = HtmlStrings(page);

            return(new HtmlContentBuilder(s));
        }
        internal static string GetDropDownRow <TPage, TEnum>(int i, IButtonForCreateDropDown <TPage, TEnum> page)
        {
            var s = "<a class=\"dropdown-item\" " +
                    $"href=\"{page.GetDropDownEntryUri(i)}\">" +
                    $"{page.GetDropDownEntryName(i)}</a>";

            return(s);
        }
        internal static List <object> HtmlStrings <TPage, TEnum>(IButtonForCreateDropDown <TPage, TEnum> page)
        {
            var l = new List <object>();

            l.Add(new HtmlString("<div class=\"dropdown\">"));
            l.Add(new HtmlString($"<button class=\"btn btn-link\" id=\"dropdownMenuButton\" data-toggle=\"dropdown\">{Captions.Create}</button>"));
            l.Add(new HtmlString("<div class=\"dropdown-menu\" aria-labelledby=\"dropdownMenuButton\">"));

            for (int i = 0; i < page.DropDownEntryCount; i++)
            {
                l.Add(new HtmlString(GetDropDownRow(i, page)));
            }
            l.Add(new HtmlString("</div>"));
            l.Add(new HtmlString("</div>"));

            return(l);
        }