code: def test_when_val_data_passed_to_mw_model_fit_then_exception_is_raised(
      temp_model_path,
  ):
      mw_model = get_multi_window_deepar(path=temp_model_path)
      with pytest.raises(
          ValueError, match="val_data should not be passed"
      ):
          mw_model.fit(
              train_data=DUMMY_TS_DATAFRAME, val_data=DUMMY_TS_DATAFRAME
          )
  
file_path: autogluon/timeseries/tests/unittests/models/test_multi_window_model.py
imports: import os
  import shutil
  import tempfile
  import pytest
  from autogluon.timeseries.models import DeepARModel, ETSModel
  from autogluon.timeseries.models.multi_window import MultiWindowBacktestingModel
  from autogluon.timeseries.splitter import ExpandingWindowSplitter
  from ..common import DUMMY_TS_DATAFRAME, dict_equal_primitive
label_desc: Use image node_id 4 for calling a global function with example usage: test_when_val_data_passed_to_mw_model_fit_then_exception_is_raised(temp_model_path) without return types