I want to add a button to the HeaderSpan of ListGrid in SmartGWT. I tried using the 'HeaderSpan.setAttribute((String property, Object value)) method but it did not work. Below is the example I tried with:- ListGrid countryGrid = new ListGrid(); HeaderSpan ident = new HeaderSpan("Identification", new String[]{"countryCode", "countryName"}); ident.setAttribute("control", new Button("Test")); countryGrid.setHeaderSpans(ident); countryGrid.draw(); Please help!