private List select()

in java/ws-server/src/main/java/com/epam/deltix/tbwg/webapp/services/grafana/GrafanaServiceImpl.java [394:429]
35 lines of code
2 McCabe index (conditional complexity)

    private List<TimeSeriesEntry> select(String streamKey, TimeRange range, long step, SelectQuery query)
            throws NoSuchStreamException, NoSuchSymbolsException, SelectBuilder2.NoSuchFieldException, WrongTypeException, NoSuchTypeException {
        SelectBuilder2 selectBuilder = constructQuery(streamKey, range, query);
        try (MessageSource<InstrumentMessage> messageSource = selectBuilder.executeRaw()) {
            Map<String, TimeSeriesEntry> entries = new HashMap<>();
            Map<String, List<Aggregation>> aggregations = new HashMap<>();
            query.getFields().values().stream()
                    .flatMap(Collection::stream)
                    .forEach(tbField -> aggregations.put(
                            tbField.getName(),
                            tbField.getAggregations().stream()
                                    .map(AggregationInfo::getName)
                                    .map(Aggregations::fromString)
                                    .collect(Collectors.toList())
                    ));
            Aggregator aggregator = new MultiAggregator(range.getFrom().toEpochMilli(), range.getTo().toEpochMilli(), step, aggregations);
            IntervalEntry entry = new IntervalEntry();
            HashSet<String> visited = new HashSet<>();
            while (aggregator.nextInterval(messageSource, entry)) {
                visited.clear();
                entry.getValues().keyIterator().forEachRemaining(key -> {
                    entries.computeIfAbsent(key, k -> new TimeSeriesEntry(key)).datapoints
                            .add(new Number[]{entry.getValues().get(key, Double.NaN), entry.getTimestamp()});
                    visited.add(key);
                });
                entries.keySet().stream()
                        .filter(key -> !visited.contains(key))
                        .forEach(key -> entries.get(key).datapoints.add(new Number[]{null, entry.getTimestamp()}));
            }
            entries.forEach((key, value) -> {
                LOG.info().append(key).append(": ").append(value.datapoints.size()).commit();
            });

            return new ArrayList<>(entries.values());
        }
    }