docstr: Test eq2 for figure 1 Peng et al (2008)
docstr_tok: ["Test","eq2","for","figure","1","Peng","et","al","(","2008",")"]
code: def test_peng_square_clustering(self):
      """Test eq2 for figure 1 Peng et al (2008)"""
      G = nx.Graph([(1, 2), (1, 3), (2, 4), (3, 4), (3, 5), (3, 6)])
      assert nx.square_clustering(G, [1])[1] == 1 / 3
  
imports: import pytest
  import networkx
label_desc: Use image node_id 7 for calling the TestSquareClustering obj's underlying member method code with example usage: obj.test_peng_square_clustering() without return types