code: @Test public void testInvoke() throws Exception {
    URL url=URL.valueOf("test://test:11/test?accesslog=true&group=dubbo&version=1.1");
    String path=DemoService.class.getResource("/").getPath();
    final URLClassLoader cl=new URLClassLoader(new java.net.URL[]{new java.net.URL("file:" + path)}){
      @Override public Class<?> loadClass(    String name) throws ClassNotFoundException {
        try {
          return findClass(name);
        }
   catch (      ClassNotFoundException e) {
          return super.loadClass(name);
        }
      }
    }
  ;
    final Class<?> clazz=cl.loadClass(DemoService.class.getCanonicalName());
    Invoker invoker=new MyInvoker(url){
      @Override public Class getInterface(){
        return clazz;
      }
      @Override public Result invoke(    Invocation invocation) throws RpcException {
        Assert.assertEquals(cl,Thread.currentThread().getContextClassLoader());
        return null;
      }
    }
  ;
    Invocation invocation=Mockito.mock(Invocation.class);
    classLoaderFilter.invoke(invoker,invocation);
  }
  