CassandraRecipientRewriteTableDAO { Mono<MappingsImpl> retrieveMappings(MappingSource source) { return executor.execute(retrieveMappingStatement.bind() .setString(USER, source.getFixedUser()) .setString(DOMAIN, source.getFixedDomain())) .map(resultSet -> cassandraUtils.convertToStream(resultSet) .map(row -> row.getString(MAPPING)) .collect(Guavate.toImmutableList())) .map(MappingsImpl::fromCollection) .filter(Predicate.not(MappingsImpl::isEmpty)); } @Inject  CassandraRecipientRewriteTableDAO(Session session, CassandraUtils cassandraUtils); Mono<Void> addMapping(MappingSource source, Mapping mapping); Flux<Pair<MappingSource, Mapping>> getAllMappings();  }
@Test void retrieveMappingsShouldReturnEmptyByDefault() { assertThat(dao.retrieveMappings(SOURCE).blockOptional()).isEmpty(); }