### Question:
DefaultNotificationFilterPreferenceManager implements NotificationFilterPreferenceManager { @Override public void deleteFilterPreference(DocumentReference user, String filterPreferenceId) throws NotificationException { try { for (NotificationFilterPreferenceProvider provider : componentManager.<NotificationFilterPreferenceProvider>getInstanceList( NotificationFilterPreferenceProvider.class)) { provider.deleteFilterPreference(user, filterPreferenceId); } } catch (ComponentLookupException e) { logger.info("Failed to remove the filter preference [{}].", filterPreferenceId, e); } }  @Override Collection<NotificationFilterPreference> getFilterPreferences(DocumentReference user); @Override Stream<NotificationFilterPreference> getFilterPreferences(
            Collection<NotificationFilterPreference> filterPreferences, NotificationFilter filter); @Override Stream<NotificationFilterPreference> getFilterPreferences(
            Collection<NotificationFilterPreference> filterPreferences, NotificationFilter filter,
            NotificationFilterType filterType); @Override Stream<NotificationFilterPreference> getFilterPreferences(
            Collection<NotificationFilterPreference> filterPreferences, NotificationFilter filter,
            NotificationFilterType filterType, NotificationFormat format); @Override void saveFilterPreferences(DocumentReference user, Set<NotificationFilterPreference> filterPreferences); @Override void deleteFilterPreference(DocumentReference user, String filterPreferenceId); @Override void setFilterPreferenceEnabled(DocumentReference user, String filterPreferenceId, boolean enabled); @Override void setStartDateForUser(DocumentReference user, Date startDate);  }### Answer:
@Test public void deleteFilterPreference() throws Exception { mocker.getComponentUnderTest().deleteFilterPreference(testUser, "myFilter"); verify(testProvider, times(1)).deleteFilterPreference(eq(testUser), eq("myFilter")); }