code: def test_persim():
      assert "PersImage" in dir(sktda)
      assert "heat" in dir(sktda)
      assert "sliced_wasserstein" in dir(sktda)
      assert "plot_diagrams" in dir(sktda)
  
label_desc: Use image node_id 2 for calling a global function with example usage: test_persim() without return types