ColumnConfig name = new ColumnConfig("name", "Name", 100);
name.setRenderer(new TreeGridCellRenderer<ModelData>());
ColumnConfig date = new ColumnConfig("author", "Author", 100);
ColumnConfig size = new ColumnConfig("genre", "Genre", 100);
ColumnModel cm = new ColumnModel(Arrays.asList(name, date, size));
TreeGrid<ModelData> tree = new TreeGrid<ModelData>(store, cm);
tree.setBorders(false);
tree.getStyle().setLeafIcon(Resources.ICONS.music());
tree.setAutoExpandColumn("name");