code: def persist_as_png(structure_dict, filepath):
      """Saves pipeline diagram to disk as png file.
  
      Args:
          structure_dict (dict): dict returned by
              :func:`~steppy.base.Step.upstream_structure`
          filepath (str): filepath to which the png with pipeline visualization should be persisted
      """
      graph = _create_graph(structure_dict)
      graph.write(filepath, format="png")
  
file_path: steppy/steppy/utils.py
imports: import logging
  import sys
  import pydot_ng
  from IPython.display import Image, display
label_desc: Use image node_id 4 for calling a global function with example usage: persist_as_png(structure_dict, filepath) without return types