code: def setup_class(cls):
      G = nx.Graph()
      G.add_edge(0, 1, weight=3)
      G.add_edge(0, 2, weight=2)
      G.add_edge(0, 3, weight=6)
      G.add_edge(0, 4, weight=4)
      G.add_edge(1, 3, weight=5)
      G.add_edge(1, 5, weight=5)
      G.add_edge(2, 4, weight=1)
      G.add_edge(3, 4, weight=2)
      G.add_edge(3, 5, weight=1)
      G.add_edge(4, 5, weight=4)
      cls.G = G
      cls.exact_weighted = {
          0: 4.0,
          1: 0.0,
          2: 8.0,
          3: 6.0,
          4: 8.0,
          5: 0.0,
      }
      cls.K = nx.krackhardt_kite_graph()
      cls.P3 = nx.path_graph(3)
      cls.P4 = nx.path_graph(4)
      cls.K5 = nx.complete_graph(5)
      cls.P2 = nx.path_graph(2)
  
      cls.C4 = nx.cycle_graph(4)
      cls.T = nx.balanced_tree(r=2, h=2)
      cls.Gb = nx.Graph()
      cls.Gb.add_edges_from(
          [(0, 1), (0, 2), (1, 3), (2, 3), (2, 4), (4, 5), (3, 5)]
      )
      cls.F = nx.florentine_families_graph()
      cls.LM = nx.les_miserables_graph()
      cls.D = nx.cycle_graph(3, create_using=nx.DiGraph())
      cls.D.add_edges_from([(3, 0), (4, 3)])
  
imports: import pytest
  import networkx
label_desc: Use image node_id 1 for calling the TestLoadCentrality obj's underlying member method code with example usage: obj.setup_class(cls) without return types