code: def test_ch_base():
      test = CHTest(m=2)
      assert test.estimate_seasonal_differencing_term(None) == 0
  
      # test really long m for random array
      random_state = check_random_state(42)
      CHTest(m=365).estimate_seasonal_differencing_term(
          random_state.rand(400)
      )
  
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 5 for calling a global function with example usage: test_ch_base() without return types