code: def _get_mock_fs(self):
      raise NotImplementedError()
  
imports: import stat
  import unittest
  import yaml
  from collections import namedtuple
  from unittest.mock import patch
  from parameterized import parameterized
  import __res
label_desc: Use image node_id 3 for calling the ArcadiaSourceFinderTestCase obj's underlying member method code with example usage: obj._get_mock_fs() without return types