private TreeNode[] selectedItems;
public TreeTableController() {
root = new DefaultTreeNode("root", null);
TreeNode node1 = new DefaultTreeNode("node", new TreeTableElement("Node1", "1st Column", "2nd Column"), root);
TreeNode node2 = new DefaultTreeNode("node", new TreeTableElement("Node2", "1st Column", "2nd Column"), root);
TreeNode node11 = new DefaultTreeNode("leaf", new TreeTableElement("Node1.1", "1st Column", "2nd Column"), node1);
TreeNode node12 = new DefaultTreeNode("leaf", new TreeTableElement("Node1.2", "1st Column", "2nd Column"), node1);
TreeNode node21 = new DefaultTreeNode("node", new TreeTableElement("Node2.1", "1st Column", "2nd Column"), node2);
TreeNode node211 = new DefaultTreeNode("leaf", new TreeTableElement("Node2.1.1", "1st Column", "2nd Column"), node21);
}