docstr: Betweenness centrality: P3 normalized
docstr_tok: ["Betweenness","centrality",":","P3","normalized"]
code: def test_P3_normalized(self):
      """Betweenness centrality: P3 normalized"""
      G = nx.path_graph(3)
      b = nx.betweenness_centrality(G, weight=None, normalized=True)
      b_answer = {0: 0.0, 1: 1.0, 2: 0.0}
      for n in sorted(G):
          assert b[n] == pytest.approx(b_answer[n], abs=1e-7)
  
imports: import pytest
  import networkx
label_desc: Use image node_id 3 for calling the TestBetweennessCentrality obj's underlying member method code with example usage: obj.test_P3_normalized() without return types