code: def test_windowbase_splitter_get_n_split_hierarchical(
      CV, fh, window_length, step_length
  ):
      """Test that WindowBaseSplitter.get_n_splits works for hierarchical data."""
      # see bugs 4971
      y = TEST_Y_PANEL_HIERARCHICAL[0]  # hierarchical data
      if _inputs_are_supported([fh, window_length, step_length]):
          cv = CV(fh, window_length, step_length)
          assert cv.get_n_splits(y) == len(
              list(cv.split(y))
          ), "get_n_splits does not equal the number of splits in the output."
  
file_path: sktime/sktime/split/base/tests/test_base.py
imports: import numpy
  import pandas
  import pytest
  from sktime.forecasting.tests._config import TEST_FHS, TEST_FHS_TIMEDELTA, TEST_STEP_LENGTHS, TEST_WINDOW_LENGTHS
  from sktime.split.base._common import _inputs_are_supported
  from sktime.split.expandingwindow import ExpandingWindowSplitter
  from sktime.split.singlewindow import SingleWindowSplitter
  from sktime.split.slidingwindow import SlidingWindowSplitter
  from sktime.utils._testing.hierarchical import _make_hierarchical
  from sktime.utils._testing.panel import _make_panel
  from sktime.utils._testing.series import _make_series
label_desc: Use image node_id 5 for calling a global function with example usage: test_windowbase_splitter_get_n_split_hierarchical(CV, fh, window_length, step_length) without return types