code: def test_tree_all_pairs_gold_example(self):
      ans = dict(tree_all_pairs_lca(self.DG))
      self.assert_has_same_pairs(self.gold, ans)
  
imports: from itertools import chain, combinations, product
  import pytest
  import networkx
label_desc: Use image node_id 6 for calling the TestTreeLCA obj's underlying member method code with example usage: obj.test_tree_all_pairs_gold_example() without return types