public URL addParameters(Map<String, String> parameters) {
        URLParam newParam = urlParam.addParameters(parameters);
        return returnURL(newParam);
    }
@Test
    void testAddParameters() throws Exception {
        URL url = URL.valueOf("dubbo://127.0.0.1:20880");
        assertURLStrDecoder(url);

        Map<String, String> parameters = new HashMap<String, String>();
        parameters.put("version", null);
        url.addParameters(parameters);
        assertURLStrDecoder(url);
    }