code: def test_triangle_and_signed_edge(self):
      G = nx.cycle_graph(3)
      G.add_edge(0, 1, weight=-1)
      G.add_edge(3, 0, weight=0)
      assert nx.clustering(G)[0] == 1 / 3
      assert nx.clustering(G, weight="weight")[0] == -1 / 3
  
imports: import pytest
  import networkx
label_desc: Use image node_id 7 for calling the TestWeightedClustering obj's underlying member method code with example usage: obj.test_triangle_and_signed_edge() without return types