private ListingProviders() throws IOException {
super();
providers = new ArrayList<ListingProvider>();
try {
CommonUtils.visitClasses(new IClassVisitor() {
public void visit(ClassLoader klassLoader, String className) {
try {
Class<?> klass = klassLoader.loadClass(className);
if (ListingProvider.class.isAssignableFrom(klass)) {
@SuppressWarnings("unchecked")