code: public static Range aggregateRange(Range dataRange, Range aggregatedRange) {
          if (aggregatedRange == null) {
              return dataRange;
          } else {
              return Ranges.sum(dataRange, aggregatedRange);
          }
      }
docs: Increases the given aggregated range with the new data range.
  <p>
  TODO: maybe this should be re-thought: it's the same as sum with
  different null handling. Maybe a RangeAggregator utility class
  that also handles numbers?
  
  @param dataRange the new data range; can't be null
  @param aggregatedRange the old aggregated range; can be null
  @return a range big enough to contain both ranges