code: def test_check_integrity(self):
      suffix = "jpg"
      files = list_files(self.path, suffix)
      for file in os.listdir(self.path):
          if file.endswith(suffix):
              self.assertIn(os.path.join(self.path, file), files)
  
imports: import json
  import os
  import tempfile
  import unittest
  from mmocr.utils import check_integrity, get_md5, is_archive, list_files, list_from_file, list_to_file
label_desc: Use image node_id 2 for calling the TestListFiles obj's underlying member method code with example usage: obj.test_check_integrity() without return types