private void toolStripMenuItemInsertUnique_Click(object sender, EventArgs e)
{
TreeNode tnParent = this.treeView.SelectedNode;
DocEntity docEntity = (DocEntity)tnParent.Tag;
DocUniqueRule docAttr = new DocUniqueRule();
docEntity.UniqueRules.Add(docAttr);
this.treeView.SelectedNode = this.LoadNode(tnParent, docAttr, docAttr.ToString(), false);
toolStripMenuItemEditRename_Click(this, e);
}