@Override
  protected StationHelper createStationHelper() throws IOException {
    TimedCollection.Dataset td = dataCollection.getPrototype();
    if (td == null) throw new RuntimeException("No datasets in the collection");

    Formatter errlog = new Formatter();
    try (FeatureDatasetPoint openDataset =
        (FeatureDatasetPoint)
            FeatureDatasetFactoryManager.open(
                FeatureType.STATION, td.getLocation(), null, errlog)) {
      StationHelper stationHelper = new StationHelper();

      List<FeatureCollection> fcList = openDataset.getPointFeatureCollectionList();
      StationTimeSeriesCollectionImpl openCollection =
          (StationTimeSeriesCollectionImpl) fcList.get(0);
      List<Station> stns = openCollection.getStations();

      for (Station s : stns) {
        StationTimeSeriesFeature stnFeature = openCollection.getStationFeature(s);
        stationHelper.addStation(
            new CompositeStationFeature(
                s, timeUnit, altUnits, stnFeature.getFeatureData(), this.dataCollection));
      }

      dataVariables = openDataset.getDataVariables();
      globalAttributes = openDataset.getGlobalAttributes();

      return stationHelper;
    }
  }
      private PointFeatureIterator getNextIterator() throws IOException {
        if (!iter.hasNext()) return null;
        TimedCollection.Dataset td = iter.next();
        Formatter errlog = new Formatter();
        currentDataset =
            (FeatureDatasetPoint)
                FeatureDatasetFactoryManager.open(
                    FeatureType.STATION, td.getLocation(), null, errlog);
        List<FeatureCollection> fcList = currentDataset.getPointFeatureCollectionList();
        StationTimeSeriesFeatureCollection stnCollection =
            (StationTimeSeriesFeatureCollection) fcList.get(0);
        Station s = stnCollection.getStation(getName());
        if (s == null) {
          System.out.printf(
              "CompositeStationFeatureIterator dataset: %s missing station %s%n",
              td.getLocation(), getName());
          return getNextIterator();
        }

        StationTimeSeriesFeature stnFeature = stnCollection.getStationFeature(s);
        if (CompositeDatasetFactory.debug)
          System.out.printf(
              "CompositeStationFeatureIterator open dataset: %s for %s%n",
              td.getLocation(), s.getName());
        return stnFeature.getPointFeatureIterator(bufferSize);
      }