@Override
    public Collection<String> allClientId() {
        return clients.keySet();
    }
@Test
    void testAllClientId() {
        Collection<String> allClientIds = ephemeralIpPortClientManager.allClientId();
        assertEquals(2, allClientIds.size());
        assertTrue(allClientIds.contains(ephemeralIpPortId));
        assertTrue(allClientIds.contains(syncedClientId));
    }