public void loadFromSnapshot(ConcurrentMap<String, IpPortBasedClient> clients) {
        ConcurrentMap<String, IpPortBasedClient> oldClients = this.clients;
        this.clients = clients;
        oldClients.clear();
    }
@Test
    void testLoadFromSnapshot() {
        ConcurrentMap<String, IpPortBasedClient> snapshotClients = new ConcurrentHashMap<>();
        snapshotClients.put(snapshotClientId, snapshotClient);
        persistentIpPortClientManager.loadFromSnapshot(snapshotClients);
        Collection<String> allClientIds = persistentIpPortClientManager.allClientId();
        assertEquals(1, allClientIds.size());
        assertTrue(allClientIds.contains(snapshotClientId));
    }