if (viewer == null || !(viewer instanceof ContentViewer)) {
if (viewer instanceof ContentViewer) {
	private int compareWithLabelProvider(Viewer viewer, Object e1, Object e2) {		if (viewer == null || !(viewer instanceof ContentViewer)) {			IBaseLabelProvider prov = ((ContentViewer) viewer).getLabelProvider();			if (prov instanceof ILabelProvider) {				ILabelProvider lprov= (ILabelProvider) prov;				String name1 = lprov.getText(e1);				String name2 = lprov.getText(e2);				if (name1 != null && name2 != null) {					return getCollator().compare(name1, name2);				}			}		}		return 0; // can't compare	}