class CassandraFirstUnseenDAO {

    public Mono<MessageUid> retrieveFirstUnread(CassandraId cassandraId) {
        return cassandraAsyncExecutor.executeSingleRow(
            readStatement.bind()
                .setUUID(MAILBOX_ID, cassandraId.asUuid()))
            .map(row -> MessageUid.of(row.getLong(UID)));
    }

    @Inject public  CassandraFirstUnseenDAO(Session session);

}