code: private static void includeColumnRecursive(List<OrcProto.Type> types,
                                               boolean[] result,
                                               int typeId) {
      result[typeId] = true;
      OrcProto.Type type = types.get(typeId);
      int children = type.getSubtypesCount();
      for(int i=0; i < children; ++i) {
        includeColumnRecursive(types, result, type.getSubtypes(i));
      }
    }
docs: Recurse down into a type subtree turning on all of the sub-columns.
  @param types the types of the file
  @param result the global view of columns that should be included
  @param typeId the root of tree to enable