public void unmarshalInternalServerError() throws JAXBException, XMLStreamException {
String xml = "<stream:error>\n" +
" <internal-server-error\n" +
" xmlns='urn:ietf:params:xml:ns:xmpp-streams'/>\n" +
" </stream:error>";
StreamError streamError = unmarshal(xml, StreamError.class);
Assert.assertTrue(streamError.getCondition() instanceof InternalServerError);
}