public TextRendererMapping <TNode> AddTextRenderer()
        {
            var render = new TextRendererMapping <TNode> (this);

            Renderers.Add(render);
            return(render);
        }
        public TextRendererMapping <TNode> AddTextRenderer(Expression <Func <TNode, string> > dataProperty, bool expand = true)
        {
            var render = new TextRendererMapping <TNode> (this, dataProperty);

            render.IsExpand = expand;
            Renderers.Add(render);
            return(render);
        }