code: def test_file_io_open(self):
      with PathManager.open(self._tmpfile, mode="r") as f:
          s = f.read()
      self.assertEqual(s, self._tmpfile_contents)
  
file_path: mmf/tests/utils/test_file_io.py
imports: import os
  import shutil
  import tempfile
  import unittest
  import uuid
  from typing import Optional
  from mmf.utils.file_io import PathManager
label_desc: Use image node_id 3 for calling the TestFileIO obj's underlying member method code with example usage: obj.test_file_io_open() without return types