private int getOffset(Session session) {
   List<MeasurementStream> streams = session.getActiveMeasurementStreams();
   for (MeasurementStream stream : streams) {
     List<Measurement> measurements = stream.getMeasurements();
     for (Measurement measurement : measurements) {
       return measurement.getTimeZoneOffsetMinutes();
     }
   }
   return 0;
 }
  public void fromUTCtoLocal(Session session) {
    if (needsTimeFix(session)) {
      fixStartEndTimeFromMeasurements(session);
    }

    int minutes = getOffset(session);
    int offset = minutes * 60 * 1000;

    Date start = session.getStart();
    Date end = session.getEnd();
    session.setStart(new Date(start.getTime() + offset));
    session.setEnd(new Date(end.getTime() + offset));

    List<MeasurementStream> streams = session.getActiveMeasurementStreams();
    for (MeasurementStream stream : streams) {
      List<Measurement> measurements = stream.getMeasurements();
      for (Measurement measurement : measurements) {
        measurement.setTime(new Date(measurement.getTime().getTime() + offset));
      }
    }
  }
 public Collection<MeasurementStream> getMeasurementStreams() {
   return newArrayList(session.getActiveMeasurementStreams());
 }