code: private static RandomTree buildRandomTree(RandomTree root, Instances instances, TreeModel treeModel) {
          Instances treeInstances = new Instances(instances);
          treeInstances.setClassIndex(getClassIndex(instances, treeModel));
  
          root.m_Info = treeInstances;
          root.m_Tree = buildRandomTreeNode(root, treeModel.getNode());
  
          return root;
      }
docs: Builds a new {@link weka.classifiers.trees.RandomTree Weka RandomTree} from the given {@link org.dmg.pmml.TreeModel PMML TreeModel}.
  
  @param root      The {@link weka.classifiers.trees.RandomTree Weka RandomTree} which is to be built.
  @param instances The {@link weka.core.Instances} with the tree's attributes.
  @param treeModel The {@link org.dmg.pmml.TreeModel PMML TreeModel} which is to be converted to a {@link weka.classifiers.trees.RandomTree Weka RandomTree}.
  @return The same {@code root} instance.