DescriptionElement descEl = factory.newDescription();
Description descComp = descEl.toComponent();
descEl.setTargetNamespace(URI.create("http://testnamespace"));
InterfaceElement interfac = descEl.addInterfaceElement();
interfac.setName(new NCName("name1"));
InterfaceImpl interfac2 = (InterfaceImpl)descEl.addInterfaceElement();
interfac2.setName(new NCName("name2"));
interfac.addExtendedInterfaceName(interfac2.getName());
interfac2.addExtendedInterfaceName(interfac.getName());
// init Interface's ref to its Description, needed for interface extension.