code: public static void addScoreDistribution(Node pmmlNode, double[] classDistribution, Instances instances) {
          if (classDistribution != null) {
  
              double sum = 0.0;
              for (int i = 0; i < classDistribution.length; i++) {
                  sum += classDistribution[i];
              }
  
              for (int i = 0; i < classDistribution.length; i++) {
                  String value = instances.classAttribute().value(i);
                  double probability;
  
                  if (sum != 0.0) {
                      probability = classDistribution[i]/sum;
                  } else {
                      probability = 1.0/classDistribution.length;
                  }
  
                  ScoreDistribution scoreDistribution = new ScoreDistribution(value, 0);
                  scoreDistribution.withConfidence(classDistribution[i]);
                  scoreDistribution.withProbability(probability);
                  pmmlNode.withScoreDistributions(scoreDistribution);
              }
          }
      }
docs: Adds a {@link org.dmg.pmml.ScoreDistribution PMML ScoreDistribution element} to the given {@link org.dmg.pmml.Node PMML Node}
  with the confidence from the given {@code classDistribution}.
  
  @param pmmlNode          The {@link org.dmg.pmml.Node PMML Node} to which add a {@link org.dmg.pmml.ScoreDistribution PMML ScoreDistribution element}.
  @param classDistribution The class distribution to calculate a score for.
  @param instances         The header {@link weka.core.Instances}.