### Question:
CustomTagService { public void contentDeletedEventHandler(@Observes ContentDeletedEvent event) { log.log(Level.FINE, "contentDeletedEventHandler called for event {0}", event); if (event != null && event.getContentId() != null) { customTagPersistenceService.deleteTagsForContent(event.getContentId()); } else { log.warning("Invalid event " + event); } }  void contentDeletedEventHandler(@Observes ContentDeletedEvent event); void contentBeforeIndexedHandler(@Observes ContentBeforeIndexedEvent event); void contributorMergedEventHandler(@Observes ContributorMergedEvent event); void contributorCodeChangedEventHandler(@Observes ContributorCodeChangedEvent event); @SuppressWarnings("unchecked") void updateSysTagsField(Map<String, Object> source);  }### Answer:
@Test public void contentDeletedEventHandler() { CustomTagService tested = getTested(); tested.contentDeletedEventHandler(null); verifyZeroInteractions(tested.customTagPersistenceService); reset(tested.customTagPersistenceService); tested.contentDeletedEventHandler(new ContentDeletedEvent(null)); verifyZeroInteractions(tested.customTagPersistenceService); reset(tested.customTagPersistenceService); tested.contentDeletedEventHandler(new ContentDeletedEvent("id")); verify(tested.customTagPersistenceService).deleteTagsForContent("id"); }