### Question:
DefaultSubscriptionService implements SubscriptionService { public void init(List<ContractEventFilter> initFilters) { if (initFilters != null && !initFilters.isEmpty()) { final List<ContractEventFilter> filtersWithStartBlock = initFilters .stream() .filter(filter -> filter.getStartBlock() != null) .collect(Collectors.toList()); if (!filtersWithStartBlock.isEmpty()) { state = SubscriptionServiceState.SYNCING_EVENTS; eventSyncService.sync(filtersWithStartBlock); } } chainServices.getNodeNames().forEach(nodeName -> subscribeToNewBlockEvents( chainServices.getNodeServices(nodeName).getBlockSubscriptionStrategy(), blockListeners)); state = SubscriptionServiceState.SUBSCRIBED; } @Autowired  DefaultSubscriptionService(ChainServicesContainer chainServices,
                                      ContractEventFilterRepository eventFilterRepository,
                                      EventeumEventBroadcaster eventeumEventBroadcaster,
                                      List<BlockListener> blockListeners,
                                      @Qualifier("eternalRetryTemplate") RetryTemplate retryTemplate,
                                      EventSyncService eventSyncService); void init(List<ContractEventFilter> initFilters); @Override ContractEventFilter registerContractEventFilter(ContractEventFilter filter, boolean broadcast); @Override @Async ContractEventFilter registerContractEventFilterWithRetries(ContractEventFilter filter, boolean broadcast); @Override List<ContractEventFilter> listContractEventFilters(); @Override void unregisterContractEventFilter(String filterId); @Override void unregisterContractEventFilter(String filterId, boolean broadcast); @Override void unsubscribeToAllSubscriptions(String nodeName); @Override SubscriptionServiceState getState();  }### Answer:
@Test public void testSubscribeToNewBlocksOnInit() { underTest.init(null); verify(mockBlockSubscriptionStrategy, times(1)).addBlockListener(mockBlockListener1); verify(mockBlockSubscriptionStrategy, times(1)).addBlockListener(mockBlockListener2); }