code: def test_list_models(multi_data_model):
      multi_data_model.list_models()
  
      multi_data_model.sagemaker_session.list_s3_files.assert_called()
      assert (
          multi_data_model.sagemaker_session.list_s3_files.called_with(
              Bucket=S3_URL_SOURCE_BUCKET, Prefix=S3_URL_SOURCE_PREFIX
          )
      )
  
imports: from __future__ import absolute_import
  import os
  import pytest
  from mock import MagicMock, Mock, call, patch
  from sagemaker.multidatamodel import MULTI_MODEL_CONTAINER_MODE
  from sagemaker.multidatamodel import MultiDataModel
  from sagemaker.mxnet import MXNetModel, MXNetPredictor
label_desc: Use image node_id 15 for calling a global function with example usage: test_list_models(multi_data_model) without return types