code: @Test public void decoratedModelshouldBeThreadSafe() throws Exception {
    final List<Transformer<WroModel>> modelTransformers=new ArrayList<Transformer<WroModel>>();
    modelTransformers.add(new WildcardExpanderModelTransformer());
    victim=DefaultWroModelFactoryDecorator.decorate(new XmlModelFactory(){
      @Override protected InputStream getModelResourceAsStream() throws IOException {
        return TestXmlModelFactory.class.getResourceAsStream("wroWithWildcardResources.xml");
      }
    }
  ,modelTransformers);
    WroTestUtils.init(victim);
    final WroModel expectedModel=victim.create();
    WroTestUtils.runConcurrently(new ContextPropagatingCallable<Void>(new Callable<Void>(){
      public Void call() throws Exception {
        Assert.assertEquals(expectedModel,victim.create());
        return null;
      }
    }
  ));
  }
  