code: def _create_graph(structure_dict):
      
      graph = pydot.Dot()
      for node in structure_dict['nodes']:
          graph.add_node(pydot.Node(node))
      for node1, node2 in structure_dict['edges']:
          graph.add_edge(pydot.Edge(node1, node2))
      return graph
docs: Creates pydot graph from the pipeline structure dict.
  
      Args:
          structure_dict (dict): dict returned by step.upstream_structure
  
      Returns:
          graph (pydot.Dot): object representing upstream pipeline structure (with regard to the current Step).