@Override
    public synchronized void
    registerProviderService(NetworkId networkId,
                            VirtualProviderService virtualProviderService) {
        Set<VirtualProviderService> services =
                servicesByNetwork.computeIfAbsent(networkId, k -> new HashSet<>());

        services.add(virtualProviderService);
    }
@Test
    public void registerProviderServiceTest() {
        TestProvider1 provider1 = new TestProvider1();
        virtualProviderManager.registerProvider(provider1);

        TestProviderService1 providerService1 = new TestProviderService1();
        virtualProviderManager.registerProviderService(NETWORK_ID1, providerService1);

        assertEquals(providerService1,
                     virtualProviderManager.getProviderService(NETWORK_ID1, TestProvider1.class));
    }