head = new Header() {
@Override
protected void onRender(Element target, int index) {
super.onRender(target, index);
adopt(leftWidgetPanel);
leftWidgetPanel.addStyleName("x-panel-toolbar");
leftWidgetPanel.setLayoutOnChange(true);
leftWidgetPanel.setStyleAttribute("float", "left");
leftWidgetPanel.getAriaSupport().setPresentation(true);
leftWidgetPanel.render(getElement());