code: def test_GGS_find_change_points(univariate_mean_shift):
      """Test the GGS core estimator."""
      ggs = GGS(k_max=10, lamb=1.0)
      pred = ggs.find_change_points(univariate_mean_shift)
      assert isinstance(pred, list)
      assert len(pred) == 5
  
imports: import numpy
  import pytest
  from sktime.annotation.ggs import GGS, GreedyGaussianSegmentation
label_desc: Use image node_id 2 for calling a global function with example usage: test_GGS_find_change_points(univariate_mean_shift) without return types