CassandraMailboxDAO { public Mono<Mailbox> retrieveMailbox(CassandraId mailboxId) { return executor.executeSingleRow(readStatement.bind() .setUUID(ID, mailboxId.asUuid()) .setConsistencyLevel(consistencyLevel)) .flatMap(row -> mailboxFromRow(row, mailboxId)); } @Inject  CassandraMailboxDAO(Session session, CassandraTypesProvider typesProvider,
                               CassandraConsistenciesConfiguration consistenciesConfiguration,
                               CassandraUtils cassandraUtils); @VisibleForTesting  CassandraMailboxDAO(Session session, CassandraTypesProvider typesProvider,
                               CassandraConsistenciesConfiguration consistenciesConfiguration); Mono<Void> save(Mailbox mailbox); Mono<Void> updatePath(CassandraId mailboxId, MailboxPath mailboxPath); Mono<Void> delete(CassandraId mailboxId); Mono<Mailbox> retrieveMailbox(CassandraId mailboxId); Flux<Mailbox> retrieveAllMailboxes();  }
@Test void retrieveMailboxShouldReturnEmptyWhenNone() { assertThat(testee.retrieveMailbox(CASSANDRA_ID_1).blockOptional()) .isEmpty(); }