{
DemoService service = new DemoServiceImpl();
URL url = URL.valueOf("dubbo://127.0.0.1:9010/com.alibaba.dubbo.rpc.DemoService?service.filter=echo");
protocol.export(proxy.getInvoker(service, DemoService.class, url));
service = proxy.getProxy(protocol.refer(DemoService.class, url));
assertEquals("123",service.echo("123"));
// cast to EchoService
EchoService echo = proxy.getProxy(protocol.refer(EchoService.class, url));
assertEquals(echo.$echo("test"), "test");
assertEquals(echo.$echo("abcdefg"), "abcdefg");
assertEquals(echo.$echo(1234), 1234);