code: def test_decorator_check_fitted():
      """
      Test Sarimax fit with pandas `y` and `exog`.
      """
  
      sarimax = Sarimax(order=(1, 1, 1))
  
      err_msg = re.escape(
          (
              "Sarimax instance is not fitted yet. Call `fit` with "
              "appropriate arguments before using this method."
          )
      )
      with pytest.raises(NotFittedError, match=err_msg):
          sarimax.predict(steps=5)
      with pytest.raises(NotFittedError, match=err_msg):
          sarimax.append(y=y)
      with pytest.raises(NotFittedError, match=err_msg):
          sarimax.apply(y=y)
      with pytest.raises(NotFittedError, match=err_msg):
          sarimax.extend(y=y)
      with pytest.raises(NotFittedError, match=err_msg):
          sarimax.params()
      with pytest.raises(NotFittedError, match=err_msg):
          sarimax.summary()
  
imports: import re
  import pytest
  import numpy
  import pandas
  from sklearn.exceptions import NotFittedError
  from skforecast.Sarimax import Sarimax
  from statsmodels.tsa.statespace.sarimax import SARIMAX
  from statsmodels.tsa.statespace.sarimax import SARIMAXResults
  from statsmodels.tsa.statespace.sarimax import SARIMAXResultsWrapper
  from .fixtures_Sarimax import y
  from .fixtures_Sarimax import y_lw
  from .fixtures_Sarimax import exog
  from .fixtures_Sarimax import exog_lw
  from .fixtures_Sarimax import exog_predict
  from .fixtures_Sarimax import exog_lw_predict
  from .fixtures_Sarimax import y_datetime
  from .fixtures_Sarimax import exog_datetime
  from .fixtures_Sarimax import exog_predict_datetime
label_desc: Use image node_id 1 for calling a global function with example usage: test_decorator_check_fitted() without return types