private void addSection(final TreeGrid treeGrid) {
final String sectionName = treeGrid.getTree().getRoot().getName();
final String sectionTitle = treeGrid.getTree().getRoot().getTitle();
this.treeGrids.put(sectionName, treeGrid);
treeGrid.addCellClickHandler(new CellClickHandler() {
@Override
public void onCellClick(CellClickEvent event) {
// We use cell click as opposed to selected changed handler
// because we want to be able to refresh even if clicking
// on an already selected node.