*/
public TreeGridSelectionPage() {
List<IGridColumn> columns = new ArrayList<IGridColumn>();
columns.add(new CheckBoxColumn("checkBox"));
columns.add(new PropertyTreeColumn(new Model("Property 1"), "userObject.property1"));
columns.add(new PropertyColumn(new Model("Property 2"), "userObject.property2"));
columns.add(new PropertyColumn(new Model("Property 3"), "userObject.property3"));
columns.add(new PropertyColumn(new Model("Property 4"), "userObject.property4"));
columns.add(new PropertyColumn(new Model("Property 5"), "userObject.property5"));
columns.add(new PropertyColumn(new Model("Property 6"), "userObject.property6"));