code: def test_cubical_graph_is_2():
      G = nx.cubical_graph()
      assert nx.bipartite.maximal_extendability(G) == 2
  
file_path: networkx/networkx/algorithms/bipartite/tests/test_extendability.py
imports: import pytest
  import networkx
label_desc: Use image node_id 6 for calling a global function with example usage: test_cubical_graph_is_2() without return types