CassandraEventDeadLettersDAO { Mono<Boolean> containEvents() { return executor.executeReturnExists(containEventsStatement.bind()); } @Inject  CassandraEventDeadLettersDAO(Session session, EventSerializer eventSerializer);   }
@Test void shouldReturnTrueWhenNoEventStored() { assertThat(cassandraEventDeadLettersDAO.containEvents().block()).isFalse(); }