public String getServiceName() {
        return serviceName;
    }
@Test
    void testGetServiceName() {
        String eventScope = "scope-001";
        String serviceName = "a";
        String groupName = "b";
        String clusters = "c";
        List<Instance> hosts = new ArrayList<>();
        Instance ins = new Instance();
        hosts.add(ins);
        InstancesDiff diff = new InstancesDiff();
        diff.setAddedInstances(hosts);
        InstancesChangeEvent event = new InstancesChangeEvent(eventScope, serviceName, groupName, clusters, hosts,
                diff);
        assertEquals(eventScope, event.scope());
        assertEquals(serviceName, event.getServiceName());
        assertEquals(clusters, event.getClusters());
        assertEquals(groupName, event.getGroupName());
        List<Instance> hosts1 = event.getHosts();
        assertEquals(hosts.size(), hosts1.size());
        assertEquals(hosts.get(0), hosts1.get(0));
        InstancesDiff diff1 = event.getInstancesDiff();
        assertTrue(diff1.hasDifferent());
        assertEquals(diff.getAddedInstances().size(), diff1.getAddedInstances().size());
        assertEquals(diff.getAddedInstances().get(0), diff.getAddedInstances().get(0));
        assertEquals(diff.getRemovedInstances().size(), diff1.getRemovedInstances().size());
        assertEquals(diff.getModifiedInstances().size(), diff1.getModifiedInstances().size());
    }