code: def test_check_cv():
      cv = SlidingWindowForecastCV(h=12)
      assert check_cv(cv) is cv
      assert isinstance(check_cv(None), RollingForecastCV)
  
      with pytest.raises(TypeError):
          check_cv("something else")
  
file_path: pmdarima/pmdarima/model_selection/tests/test_split.py
imports: from pmdarima.compat.pytest import pytest_error_str
  from pmdarima.model_selection import RollingForecastCV, SlidingWindowForecastCV, check_cv, train_test_split
  from pmdarima.datasets import load_wineind
  import pytest
  import numpy
  from numpy.testing import assert_array_equal
label_desc: Use image node_id 5 for calling a global function with example usage: test_check_cv() without return types