code: def setup_class(cls):
      cls.G = nx.Graph(name="test")
      e = [
          ("a", "b"),
          ("b", "c"),
          ("c", "d"),
          ("d", "e"),
          ("e", "f"),
          ("a", "f"),
      ]
      cls.G.add_edges_from(e)
      cls.G.add_nodes_from(["a", "c", "e"], bipartite=0)
      cls.G.add_nodes_from(["b", "d", "f"], bipartite=1)
      cls.G.add_node("g", bipartite=0)
      cls.DG = nx.DiGraph(cls.G)
      cls.MG = nx.MultiGraph()
      cls.MG.add_edges_from([(1, 2), (1, 2), (1, 2)])
      cls.MG.add_node(1, bipartite=0)
      cls.MG.add_node(2, bipartite=1)
  
imports: import io
  import pytest
  import networkx
  from networkx.algorithms import bipartite
  from networkx.utils import edges_equal, graphs_equal, nodes_equal
label_desc: Use image node_id 1 for calling the TestEdgelist obj's underlying member method code with example usage: obj.setup_class(cls) without return types