@Override
    public Collection<String> searchServiceName(String namespaceId, String expr) throws NacosException {
        String regex = Constants.ANY_PATTERN + expr + Constants.ANY_PATTERN;
        Collection<String> result = new HashSet<>();
        for (Service each : ServiceManager.getInstance().getSingletons(namespaceId)) {
            String groupedServiceName = each.getGroupedServiceName();
            if (groupedServiceName.matches(regex)) {
                result.add(groupedServiceName);
            }
        }
        return result;
    }
@Test
    void testSearchServiceName() throws NacosException {
        Collection<String> res = serviceOperatorV2.searchServiceName("A", "");
        assertEquals(1, res.size());
    }