docstr: Group betweenness centrality value of 0
docstr_tok: ["Group","betweenness","centrality","value","of","0"]
code: def test_group_betweenness_value_zero(self):
      """
      Group betweenness centrality value of 0
      """
      G = nx.cycle_graph(6)
      C = [0, 1, 5]
      b = nx.group_betweenness_centrality(
          G, C, weight=None, normalized=False
      )
      b_answer = 0.0
      assert b == b_answer
  
imports: import pytest
  import networkx
label_desc: Use image node_id 5 for calling the TestGroupBetweennessCentrality obj's underlying member method code with example usage: obj.test_group_betweenness_value_zero() without return types