docstr: Betweenness centrality: P4 normalized
docstr_tok: ["Betweenness","centrality",":","P4","normalized"]
code: def test_P4_normalized(self):
      """Betweenness centrality: P4 normalized"""
      G = nx.path_graph(4)
      b = nx.current_flow_betweenness_centrality_subset(
          G, list(G), list(G), normalized=True
      )
      b_answer = nx.current_flow_betweenness_centrality(
          G, normalized=True
      )
      for n in sorted(G):
          assert b[n] == pytest.approx(b_answer[n], abs=1e-7)
  
file_path: networkx/networkx/algorithms/centrality/tests/test_current_flow_betweenness_centrality_subset.py
imports: import pytest
  import networkx
  from networkx import edge_current_flow_betweenness_centrality
  from networkx import edge_current_flow_betweenness_centrality_subset
label_desc: Use image node_id 3 for calling the TestFlowBetweennessCentrality obj's underlying member method code with example usage: obj.test_P4_normalized() without return types