code: def setup_class(cls):
      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.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)]
      )
  
      F = nx.florentine_families_graph()
      cls.F = F
  
      cls.LM = nx.les_miserables_graph()
  
      # Create random undirected, unweighted graph for testing incremental version
      cls.undirected_G = nx.fast_gnp_random_graph(
          n=100, p=0.6, seed=123
      )
      cls.undirected_G_cc = nx.closeness_centrality(cls.undirected_G)
  
file_path: networkx/networkx/algorithms/centrality/tests/test_closeness_centrality.py
imports: import pytest
  import networkx
label_desc: Use image node_id 1 for calling the TestClosenessCentrality obj's underlying member method code with example usage: obj.setup_class(cls) without return types