### Question:
CalendarServiceImpl implements CalendarService, UserDataDeletable { @Override public boolean addEntryTo(final OlatCalendar cal, final CalendarEntry calendarEntry) { Boolean persistSuccessful = calendarDao.addEventTo(cal, calendarEntry); informAboutCalendarChange(cal); return persistSuccessful.booleanValue(); } private  CalendarServiceImpl();   CalendarServiceImpl(CalendarDao calendarDao, CoordinatorManager coordinatorManager); @Override CalendarConfig findCalendarConfigForIdentity(final OlatCalendar calendar, final Preferences userGuiPreferences); @Override void saveCalendarConfigForIdentity(final CalendarConfig config, final OlatCalendar calendar, final Preferences userGuiPreferences); @Override boolean addEntryTo(final OlatCalendar cal, final CalendarEntry calendarEntry); boolean updateEntryFrom(final OlatCalendar cal, final CalendarEntry calendarEntry); boolean removeEntryFrom(final OlatCalendar cal, final CalendarEntry calendarEntry); void informAboutCalendarChange(final OlatCalendar cal); @Override OlatCalendar getPersonalCalendar(final Identity identity); @Override OlatCalendar getImportedCalendar(final Identity identity, final String calendarName); @Override OlatCalendar getGroupCalendar(final BusinessGroup businessGroup); @Override OlatCalendar getCourseCalendar(final ICourse course); @Override void deletePersonalCalendar(final Identity identity); @Override void deleteGroupCalendar(final BusinessGroup businessGroup); @Override void deleteCourseCalendar(final ICourse course); @Override void deleteUserData(final Identity identity, final String newDeletedUserName); @Override boolean calendarExists(String calendarType, String calendarID); @Override Calendar readCalendar(String type, String calendarID); @Override File getCalendarFile(String type, String calendarID); @Override OlatCalendar getCalendar(String type, String calendarID); @Override boolean deleteCalendar(String calendarType, String calendarID); @Override OlatCalendar buildCalendarFrom(String calendarContent, String calType, String calId); @Override boolean persistCalendar(OlatCalendar calendar); @Override void writeCalendarToFile(String calendarId, String calendarContent);  }### Answer:
@Test public void testAddEventTo() { boolean result = calendarServiceImpl.addEntryTo(cal, calendarEntry); verify(calendarManagerMock).addEventTo(cal, calendarEntry); assertTrue("Event was not triggered, missing fireEventToListenersOf(...)", eventBusMock.firedEvent); }