code: def setup_class(cls):
      # simple graph
      connected_chordal_G = nx.Graph()
      connected_chordal_G.add_edges_from(
          [
              (1, 2),
              (1, 3),
              (2, 3),
              (2, 4),
              (3, 4),
              (3, 5),
              (3, 6),
              (4, 5),
              (4, 6),
              (5, 6),
          ]
      )
      cls.connected_chordal_G = connected_chordal_G
  
      chordal_G = nx.Graph()
      chordal_G.add_edges_from(
          [
              (1, 2),
              (1, 3),
              (2, 3),
              (2, 4),
              (3, 4),
              (3, 5),
              (3, 6),
              (4, 5),
              (4, 6),
              (5, 6),
              (7, 8),
          ]
      )
      chordal_G.add_node(9)
      cls.chordal_G = chordal_G
  
      non_chordal_G = nx.Graph()
      non_chordal_G.add_edges_from(
          [(1, 2), (1, 3), (2, 4), (2, 5), (3, 4), (3, 5)]
      )
      cls.non_chordal_G = non_chordal_G
  
      self_loop_G = nx.Graph()
      self_loop_G.add_edges_from([(1, 1)])
      cls.self_loop_G = self_loop_G
  
file_path: networkx/networkx/algorithms/tests/test_chordal.py
imports: import pytest
  import networkx
label_desc: Use image node_id 1 for calling the TestMCS obj's underlying member method code with example usage: obj.setup_class(cls) without return types