@Override
 public final List<ValueRange> getGroupingModel(
     DataTable data, double upperBound, double lowerBound) {
   StaticDebug.debug("Create grouping with upper bound: " + upperBound);
   StaticDebug.debug("and lower bound: " + lowerBound);
   return createGroupingModel(data, upperBound, lowerBound);
 }
 private void debug(String msg) {
   StaticDebug.debug("PlotData: " + msg);
 }