code: def test_all_pairs_lca_identity(self):
      G = nx.DiGraph()
      G.add_node(3)
      assert nx.lowest_common_ancestor(G, 3, 3) == 3
  
imports: from itertools import chain, combinations, product
  import pytest
  import networkx
label_desc: Use image node_id 14 for calling the TestDAGLCA obj's underlying member method code with example usage: obj.test_all_pairs_lca_identity() without return types