code: def test_ch_test_long(m, chstat, expected):
      chtest = CHTest(m=m)
      y = np.random.rand(
          m * 3
      )  # very long, but mock makes it not matter
  
      mock_sdtest = lambda *args, **kwargs: chstat
      with mock.patch.object(chtest, "_sd_test", mock_sdtest):
          res = chtest.estimate_seasonal_differencing_term(y)
  
      assert expected == res
  
imports: from pmdarima.arima.seasonality import CHTest, decompose, OCSBTest
  from pmdarima.arima.utils import nsdiffs
  from pmdarima.compat.pytest import pytest_error_str
  from pmdarima.datasets import load_airpassengers, load_ausbeer, load_austres, load_wineind
  import numpy
  from numpy.testing import assert_almost_equal, assert_array_equal
  from sklearn.utils.validation import check_random_state
  import pytest
  from unittest import mock
label_desc: Use image node_id 4 for calling a global function with example usage: test_ch_test_long(m, chstat, expected) without return types