docs: @SuppressWarnings("unused")
      private int cordToIndex(DataPointPair<Integer> dataPoint)
      {
          DataPoint dp = dataPoint.getDataPoint();
          int index = 0;
          for(int i = 0; i < dimSize.length; i++)
              index = dp.getCategoricalValue(realIndexToCatIndex[i]) + dimSize[i]*index;
          return index;
      }