private static TimeInterval encodeTimeInterval(Range<Instant> nativeInterval, Kind metricKind) {

    TimeInterval encodedInterval =
        new TimeInterval().setStartTime(nativeInterval.lowerEndpoint().toString());

    Instant endTimestamp =
        nativeInterval.isEmpty() && metricKind != Kind.GAUGE
            ? nativeInterval.upperEndpoint().plusMillis(1)
            : nativeInterval.upperEndpoint();

    return encodedInterval.setEndTime(endTimestamp.toString());
  }
 

/**
 * Convert a Spectator metric Meter into a Stackdriver TimeSeries entry.
 *
 * @param descriptorType The Stackdriver MetricDescriptorType name for the measurement.
 * @param measurement The Spectator Measurement to encode.
 * @return The Stackdriver TimeSeries equivalent for the measurement.
 */
public TimeSeries measurementToTimeSeries(
    String descriptorType, Registry registry, Meter meter, Measurement measurement) {
  Map<String, String> labels =
      cache.tagsToTimeSeriesLabels(descriptorType, measurement.id().tags());

  long millis = measurement.timestamp();
  double value = measurement.value();

  TimeInterval timeInterval = new TimeInterval();
  Date date = new Date(millis);
  timeInterval.setEndTime(rfc3339.format(date));

  String descriptorKind = cache.descriptorTypeToKind(descriptorType, registry, meter);
  if (descriptorKind == "CUMULATIVE") {
    timeInterval.setStartTime(counterStartTimeRfc3339);
  }

  TypedValue typedValue = new TypedValue();
  typedValue.setDoubleValue(value);

  Point point = new Point();
  point.setValue(typedValue);
  point.setInterval(timeInterval);

  Metric metric = new Metric();
  metric.setType(descriptorType);
  metric.setLabels(labels);

  TimeSeries ts = new TimeSeries();
  ts.setResource(monitoredResource);
  ts.setMetric(metric);
  ts.setMetricKind(descriptorKind);
  ts.setValueType("DOUBLE");
  ts.setPoints(Lists.<Point>newArrayList(point));

  return ts;
}