code: def test_coco_cache_files_writer(self):
      tempdir = self.create_tempdir()
      coco_dir = tasks_test_utils.get_test_data_path("coco_data")
      label_map = dataset_util.get_label_map_coco(coco_dir)
      cache_writer = dataset_util.COCOCacheFilesWriter(label_map)
      cache_files = dataset_util.get_cache_files_coco(
          coco_dir, cache_dir=tempdir
      )
      cache_writer.write_files(cache_files, coco_dir)
      self._validate_cache_files(cache_files, 3)
  
imports: import hashlib
  import json
  import os
  import shutil
  from unittest import mock
  import tensorflow
  from mediapipe.model_maker.python.vision.core import test_utils
  from mediapipe.model_maker.python.vision.object_detector import dataset_util
  from mediapipe.tasks.python.test import test_utils
label_desc: Use image node_id 14 for calling the DatasetUtilTest obj's underlying member method code with example usage: obj.test_coco_cache_files_writer() without return types