code: def test_file_io_async(self):
      # ioPath `PathManager` is initialized after the first `opena` call.
      try:
          from fairseq.file_io import PathManager
  
          _asyncfile = os.path.join(self._tmpdir, "async.txt")
          f = PathManager.opena(_asyncfile, "wb")
          f.close()
  
      finally:
          self.assertTrue(PathManager.async_close())
  
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 5 for calling the TestFileIO obj's underlying member method code with example usage: obj.test_file_io_async() without return types