public String reqApi(String api, Map<String, String> params, String method) throws NacosException {
        return reqApi(api, params, Collections.EMPTY_MAP, method);
    }
@Test
    void testRegApiForDomain() throws NacosException {
        assertThrows(NacosException.class, () -> {
            Map<String, String> params = new HashMap<>();
            when(mgr.isDomain()).thenReturn(true);
            when(mgr.getNacosDomain()).thenReturn("http://test.nacos.domain");
            clientProxy.reqApi("api", params, Collections.emptyMap(), Collections.emptyList(), HttpMethod.GET);
            
        });
        
    }