code: def getCanonical():
      G = nx.Graph()
      G.add_node("A", label="A")
      G.add_node("B", label="B")
      G.add_node("C", label="C")
      G.add_node("D", label="D")
      G.add_edge("A", "B", label="a-b")
      G.add_edge("B", "C", label="b-c")
      G.add_edge("B", "D", label="b-d")
      return G
  
imports: import pytest
  import networkx
  from networkx.algorithms.similarity import graph_edit_distance, optimal_edit_paths, optimize_graph_edit_distance
  from networkx.generators.classic import circular_ladder_graph, cycle_graph, path_graph, wheel_graph
label_desc: Use image node_id 3 for calling a global function with example usage: getCanonical() and returns: G