// code copied from AbstractHistoricalTimeSeriesLoader due to lack of multiple inheritance
@Override
public Map<ExternalId, UniqueId> loadTimeSeries(
Set<ExternalId> identifiers, String dataProvider, String dataField, LocalDate startDate, LocalDate endDate) {
HistoricalTimeSeriesLoaderRequest request = HistoricalTimeSeriesLoaderRequest.create(identifiers, dataProvider, dataField, startDate, endDate);
HistoricalTimeSeriesLoaderResult result = loadTimeSeries(request);
return result.getResultMap();
}