code: def test_init_TypeError_when_window_size_is_not_int():
      """
      Test TypeError is raised when window_size is not an int.
      """
      window_size = "not_valid_type"
      err_msg = re.escape(
          f"Argument `window_size` must be an int. Got {type(window_size)}."
      )
      with pytest.raises(TypeError, match=err_msg):
          ForecasterAutoregMultiSeriesCustom(
              regressor=LinearRegression(),
              fun_predictors=create_predictors,
              window_size=window_size,
          )
  
file_path: skforecast/skforecast/ForecasterAutoregMultiSeriesCustom/tests/test_init.py
imports: import re
  import pytest
  from skforecast.ForecasterAutoregMultiSeriesCustom import ForecasterAutoregMultiSeriesCustom
  from sklearn.linear_model import LinearRegression
label_desc: Use image node_id 2 for calling a global function with example usage: test_init_TypeError_when_window_size_is_not_int() without return types