@Override
    public void close() {
        if (!ObjectUtils.isEmpty(watchConfigChangeListener)) {
            configService.removeChangeListener(watchConfigChangeListener);
        }
    }
@Test
    public void testClose() {
        Config configService = mock(Config.class);
        ApolloDataService apolloDataService = new ApolloDataService(configService, null,
                Collections.emptyList(), Collections.emptyList(), Collections.emptyList(), Collections.emptyList());
        apolloDataService.close();
    }