code: def _validate_mar(patches):
      if platform.system() == "Windows":
          patches.path_exists.assert_called_once_with(
              "/Users/dummyUser\\some-model.mar"
          )
      else:
          patches.path_exists.assert_called_once_with(
              "/Users/dummyUser/some-model.mar"
          )
  
file_path: serve/model-archiver/model_archiver/tests/unit_tests/test_model_packaging_utils.py
imports: import json
  import platform
  from collections import namedtuple
  from pathlib import Path
  import pytest
  from model_archiver import ModelArchiverConfig
  from model_archiver.manifest_components.manifest import RuntimeType
  from model_archiver.model_archiver_error import ModelArchiverError
  from model_archiver.model_packaging_utils import ModelExportUtils
label_desc: Use image node_id 1 for calling a global function with example usage: _validate_mar(patches) without return types