code: def test_IGTS_find_change_points(multivariate_mean_shift):
      """Test the IGTS core estimator."""
      igts = IGTS(k_max=3, step=1)
      pred = igts.find_change_points(multivariate_mean_shift)
      assert isinstance(pred, list)
      assert len(pred) == 5
  
file_path: sktime/sktime/annotation/tests/test_igts.py
imports: import numpy
  import pytest
  from sktime.annotation.igts import IGTS, InformationGainSegmentation, entropy
label_desc: Use image node_id 5 for calling a global function with example usage: test_IGTS_find_change_points(multivariate_mean_shift) without return types