code: def test_unweighted_digraph(self):
      G = nx.DiGraph(nx.cycle_graph(3))
      vitality = nx.closeness_vitality(G)
      assert vitality == {0: 4, 1: 4, 2: 4}
  
file_path: networkx/networkx/algorithms/tests/test_vitality.py
imports: import networkx
label_desc: Use image node_id 3 for calling the TestClosenessVitality obj's underlying member method code with example usage: obj.test_unweighted_digraph() without return types