code: def test_fit_in_sample_residuals_not_stored():
      """
      Test that values of in_sample_residuals are not stored after fitting
      when `store_in_sample_residuals=False`.
      """
      forecaster = ForecasterAutoregCustom(
          regressor=LinearRegression(),
          fun_predictors=create_predictors,
          window_size=5,
      )
      forecaster.fit(
          y=pd.Series(np.arange(10)), store_in_sample_residuals=False
      )
      results = forecaster.in_sample_residuals
  
      assert results is None
  
file_path: skforecast/skforecast/ForecasterAutoregCustom/tests/test_fit.py
imports: import numpy
  import pandas
  from skforecast.ForecasterAutoregCustom import ForecasterAutoregCustom
  from sklearn.linear_model import LinearRegression
  from .fixtures_ForecasterAutoregCustom import y
label_desc: Use image node_id 7 for calling a global function with example usage: test_fit_in_sample_residuals_not_stored() without return types