private void addMultipleNewNodesToolStripMenuItem_Click(object sender, EventArgs e)
{
TreeNode selectedTreeNode = multiSelectTreeviewElementsGroups.SelectedNode;
if (selectedTreeNode == null)
AddMultipleNodesWithPrompt();
else
AddMultipleNodesWithPrompt(selectedTreeNode.Tag as ElementNode);
PopulateFormWithNode(_displayedNode, true);
}