code: def test_caveman_graph():
      G = nx.caveman_graph(4, 3)
      assert len(G) == 12
  
      G = nx.caveman_graph(5, 1)
      E5 = nx.empty_graph(5)
      assert nx.is_isomorphic(G, E5)
  
      G = nx.caveman_graph(1, 5)
      K5 = nx.complete_graph(5)
      assert nx.is_isomorphic(G, K5)
  
imports: import pytest
  import networkx
label_desc: Use image node_id 5 for calling a global function with example usage: test_caveman_graph() without return types