def METHOD_NAME(self,
                                                                    mock_isdir,
                                                                    mock_listdir):
    mock_isdir.side_effect = [True, False, True]
    mock_listdir.side_effect = [['file1'], ['file1']]
    self.assertRaises(errors.ConfigValidatorPolicyLibraryError, self.scanner.verify_policy_library)
    self.assertEqual(mock_isdir.call_count, 2)