How to optimize dataset aggregation on top of java objects dataset

could you please support me on stupid question:

I have some Java class:

public class ProbePoint implements Serializable, Cloneable {
    private long arrivalTimeMillis = 0;
    private long captureTimeMillis = 0;
//...
}
public class Trip implements Serializable, Cloneable {
    private ArrayList<ProbePoint> points = new ArrayList<>();
//...
}

I have Dataset[Trip]. I need to collect some min/max values. What would be better implementation of next:

public class DataRanges implements Serializable {
    private long minCaptureTs;
    private long maxArrivalTs;

}

 val timesDs: Dataset[DataRanges] = trips.mapPartitions(t => {
      var minCaptTime = Long.MaxValue
      var maxArrTime = Long.MinValue
      t.foreach(f => {
        if (f.points.head < minCaptTime) minCaptTime = f.points.head
        if (f.points.last.getArrivalTimeMillis > maxArrTime) maxArrTime = f.points.last.getArrivalTimeMillis
      })
      Iterator[DataRanges](
        new DataRanges(minStartTime, maxEndTime, minArrTime, maxArrTime))
    })(Encoders.bean(classOf[DataRanges]))
    val times = timesDs.agg(min("minCaptureTs"), max("maxArrivalTs")).head()
}
}