code: def test_export_model_method_tar(self, patches):
      self.config.archive_format = "tgz"
      patches.export_utils.check_mar_already_exists.return_value = (
          "/Users/dummyUser/"
      )
      patches.export_utils.check_custom_model_types.return_value = (
          "/Users/dummyUser",
          ["a.txt", "b.txt"],
      )
  
      package_model(
          self.config,
          ModelExportUtils.generate_manifest_json(self.config),
      )
      patches.export_utils.validate_inputs.assert_called()
      patches.export_utils.archive.assert_called()
  
file_path: serve/model-archiver/model_archiver/tests/unit_tests/test_model_packaging.py
imports: from collections import namedtuple
  import pytest
  from model_archiver import ModelArchiverConfig
  from model_archiver.manifest_components.manifest import RuntimeType
  from model_archiver.model_packaging import generate_model_archive, package_model
  from model_archiver.model_packaging_utils import ModelExportUtils
label_desc: Use image node_id 4 for calling the TestModelPackaging obj's underlying member method code with example usage: obj.test_export_model_method_tar(patches) without return types