### Question:
NotificationService extends AbstractService { public void removeSubscription(final Subscription subscription) { notNull(subscription, "subscription"); notNull(subscription.getMeta(), "subscription.meta"); notEmpty(subscription.getMeta().getUri(), "subscription.meta.uri"); try { restTemplate.delete(subscription.getMeta().getUri()); } catch (GoodDataRestException | RestClientException e) { throw new GoodDataException("Unable to delete subscription", e); } } NotificationService(final RestTemplate restTemplate, final GoodDataSettings settings); void triggerEvent(final Project project, final ProjectEvent event); Channel createChannel(final Account account, final Channel channel); void removeChannel(final Channel channel); Subscription createSubscription(final Project project, final Account account, final Subscription subscription); void removeSubscription(final Subscription subscription);  }### Answer:
@Test(expectedExceptions = IllegalArgumentException.class) public void testRemoveSubscriptionNullSubscription() throws Exception { notificationService.removeSubscription(null); }
@Test(expectedExceptions = IllegalArgumentException.class) public void testRemoveSubscriptionEmptyUri() throws Exception { notificationService.removeSubscription(mock(Subscription.class)); }