protected override void OnExecuted(EventArgs e)
        {
            base.OnExecuted(e);
            ConfigurationSourceSectionNode node = ChildNode as ConfigurationSourceSectionNode;
            Debug.Assert(node != null);

            SystemConfigurationSourceElementNode sourceNode = new SystemConfigurationSourceElementNode();
            node.AddNode(sourceNode);
            node.SelectedSource = sourceNode;
        }
        protected override void OnExecuted(EventArgs e)
        {
            base.OnExecuted(e);
            ConfigurationSourceSectionNode node = ChildNode as ConfigurationSourceSectionNode;

            Debug.Assert(node != null);

            SystemConfigurationSourceElementNode sourceNode = new SystemConfigurationSourceElementNode();

            node.AddNode(sourceNode);
            node.SelectedSource = sourceNode;
        }