code: public ReliabilityDiagram getReliabilityDiagram(int classIdx) {
  
          INDArray totalCountBins = rDiagBinTotalCount.getColumn(classIdx);
          INDArray countPositiveBins = rDiagBinPosCount.getColumn(classIdx);
  
          double[] meanPredictionBins = rDiagBinSumPredictions.getColumn(classIdx).castTo(DataType.DOUBLE)
                  .div(totalCountBins.castTo(DataType.DOUBLE)).data().asDouble();
  
          double[] fracPositives = countPositiveBins.castTo(DataType.DOUBLE).div(totalCountBins.castTo(DataType.DOUBLE)).data().asDouble();
  
          if (excludeEmptyBins) {
              val condition = new MatchCondition(totalCountBins, Conditions.equals(0));
              int numZeroBins = Nd4j.getExecutioner().exec(condition).getInt(0);
              if (numZeroBins != 0) {
                  double[] mpb = meanPredictionBins;
                  double[] fp = fracPositives;
  
                  // FIXME: int cast
                  meanPredictionBins = new double[(int) (totalCountBins.length() - numZeroBins)];
                  fracPositives = new double[meanPredictionBins.length];
                  int j = 0;
                  for (int i = 0; i < mpb.length; i++) {
                      if (totalCountBins.getDouble(i) != 0) {
                          meanPredictionBins[j] = mpb[i];
                          fracPositives[j] = fp[i];
                          j++;
                      }
                  }
              }
          }
          String title = "Reliability Diagram: Class " + classIdx;
          return new ReliabilityDiagram(title, meanPredictionBins, fracPositives);
      }
docs: Get the reliability diagram for the specified class
  
  @param classIdx Index of the class to get the reliability diagram for