HttpServletResponse response = mock(HttpServletResponse.class);
when(response.getWriter()).thenReturn(new PrintWriter(stream));
DefaultTypeNameExtractor extractor = new DefaultTypeNameExtractor();
HibernateProxyInitializer initializer = new HibernateProxyInitializer();
XStreamBuilder builder = XStreamBuilderImpl.cleanInstance(new MessageConverter());
XStreamJSONSerialization jsonSerialization = new XStreamJSONSerialization(response, extractor, initializer, builder);
XStreamXMLSerialization xmlSerialization = new XStreamXMLSerialization(response, extractor, initializer, builder);
Container container = mock(Container.class);
when(container.instanceFor(JSONSerialization.class)).thenReturn(jsonSerialization);