protected override void BuildRenderTree(RenderTreeBuilder builder)
        {
            int seq = -1;

            builder.OpenElement(++seq, "div");
            builder.AddAttribute(++seq, "class", "Integrant.Element.Component.TabbedPanel.Panel");
            builder.AddAttribute(++seq, "hidden", TabbedPanelContainer.FocusedID() != ID);

            builder.AddContent(++seq, ChildContent);

            builder.CloseElement();
        }
        protected override void BuildRenderTree(RenderTreeBuilder builder)
        {
            int seq = -1;

            builder.OpenElement(++seq, "div");
            builder.AddAttribute(++seq, "class", "Integrant.Element.Component.TabbedPanel.Tab" +
                                 (TabbedPanelContainer.FocusedID() == ID
                                                     ? " Integrant.Element.Component.TabbedPanel.Tab:Focused"
                                                     : ""));
            @builder.AddAttribute(++seq, "onclick", EventCallback.Factory.Create <MouseEventArgs>(this, OnClick));

            builder.AddContent(++seq, ChildContent);

            builder.CloseElement();
        }