code: def _store_page(self, extension, page_id):
      page = self.pages[page_id]
      with open(
          split_all_ext(page_id)[0] + extension, "w", encoding="utf-8"
      ) as f:
          f.write(
              etree.tounicode(page.getroottree(), pretty_print=True)
          )
  
imports: import os
  from copy import deepcopy
  from dataclasses import dataclass, field
  from random import shuffle
  import math
  import numpy
  from paiargparse import pai_dataclass, pai_meta
  from tfaip.data.pipeline.definitions import PipelineMode, INPUT_PROCESSOR, TARGETS_PROCESSOR
  from tqdm import tqdm
  from lxml import etree
  import cv2
  from typing import List, Generator, Optional, Iterable, Dict, Any, Tuple
  from enum import IntEnum
  from calamari_ocr.ocr.dataset.datareader.base import CalamariDataGenerator, CalamariDataGeneratorParams, InputSample, SampleMeta
  from calamari_ocr.utils import split_all_ext, filename, glob_all
  from calamari_ocr.ocr.predict.params import Prediction
  import logging
label_desc: Use image node_id 16 for calling the PageXMLReader obj's underlying member method code with example usage: obj._store_page(extension, page_id) without return types