code: def test_pw_trafo_pipeline_mul_dunder():
      """Tests creation of pairwise panel trafo pipelines using mul dunder."""
      from sktime.transformations.series.exponent import (
          ExponentTransformer,
      )
  
      t3 = EditDist()
      t1 = ExponentTransformer(2)
      t2 = ExponentTransformer(0.5)
  
      m3 = t3.transform(X1, X2)
  
      t23 = t2 * t3
      assert isinstance(t23, PwTrafoPanelPipeline)
      assert len(t23.transformers) == 1
  
      m23 = t23.transform(X1, X2)
      X1t = t2.clone().fit_transform(X1)
      X2t = t2.clone().fit_transform(X2)
      m23_manual = t3.transform(X1t, X2t)
      assert np.allclose(m23, m23_manual)
  
      t123 = t1 * t2 * t3
      assert isinstance(t123, PwTrafoPanelPipeline)
      assert len(t123.transformers) == 2
  
      m123 = t123.transform(X1, X2)
  
      assert np.allclose(m123, m3)
  
file_path: sktime/sktime/dists_kernels/tests/test_dist_kernels_dunders.py
imports: import numpy
  import pytest
  from sktime.dists_kernels.algebra import CombinedDistance
  from sktime.dists_kernels.compose import PwTrafoPanelPipeline
  from sktime.dists_kernels.edit_dist import EditDist
  from sktime.utils._testing.panel import _make_panel_X
label_desc: Use image node_id 4 for calling a global function with example usage: test_pw_trafo_pipeline_mul_dunder() without return types