code: def test_set_dir(self):
      logger.set_dir("./logger_dir")
      temp_file = "./logger_dir/tmp.file"
      with open(temp_file, "w") as t_file:
          t_file.write("Are you OK? From Mr.Lei")
      self.assertTrue(os.path.isfile(temp_file))
      logger.set_dir("./logger_dir")
      self.assertFalse(os.path.isfile(temp_file))
  
file_path: PARL/parl/utils/tests/logger_test.py
imports: import unittest
  from parl.utils import logger
  import threading
  import os.path
label_desc: Use image node_id 4 for calling the TestLogger obj's underlying member method code with example usage: obj.test_set_dir() without return types