### Question:
SubscriptionService implements SubscriptionManager { @Override public List<Subscription> getAllSubscriptions(int limit) { List<Subscription> result = new ArrayList<Subscription>(); result.addAll(subscriptionId2Subscription.values()); if (limit > 0) { if (limit < result.size()) { result = result.subList(0, limit); } } return result; } SubscriptionService(); @Override URI subscribe(SubscriptionRequest subscriptionRequest); @Override void unsubscribe(URI id); @Override Subscription updateSubscription(SubscriptionRequest subscriptionRequest); @Override List<Subscription> getAllSubscriptions(int limit); @Override Subscription getSubscription(String subscriptionId); @KafkaListener(topics = "${entity.create.topic}", groupId = "submanager") void handleCreate(Message<byte[]> message); @KafkaListener(topics = "${entity.update.topic}", groupId = "submanager") void handleUpdate(Message<byte[]> message); @KafkaListener(topics = "${entity.append.topic}", groupId = "submanager") void handleAppend(Message<byte[]> message); @KafkaListener(topics = "${entity.delete.topic}", groupId = "submanager") void handleDelete(Message<byte[]> message); @KafkaListener(topics = "${csource.notification.topic}", groupId = "submanager") void handleCSourceNotification(Message<byte[]> message); @Override void remoteNotify(String id, Notification notification); void reportNotification(String subId, Long now); void reportFailedNotification(String subId, Long now); void reportSuccessfulNotification(String subId, Long now);  }### Answer:
@Test public void getAllSubscriptionsTest() { List<Subscription> result=manager.getAllSubscriptions(0); assertNotNull(result); }