code: def test_file_io(self):
      from fairseq.file_io import PathManager
  
      with PathManager.open(
          os.path.join(self._tmpdir, "test.txt"), "r"
      ) as f:
          s = f.read()
      self.assertEqual(s, self._tmpfile_contents)
  
file_path: fairseq/tests/test_file_io.py
imports: import os
  import shutil
  import sys
  import tempfile
  import unittest
  from typing import Optional
  from unittest.mock import MagicMock
label_desc: Use image node_id 3 for calling the TestFileIO obj's underlying member method code with example usage: obj.test_file_io() without return types