code: def test_trivial():
      print("trivial test")
  
      # back to an undirected graph
      t1 = nx.Graph()
      t1.add_node("a")
      root1 = "a"
  
      t2 = nx.Graph()
      t2.add_node("n")
      root2 = "n"
  
      isomorphism = rooted_tree_isomorphism(t1, root1, t2, root2)
  
      assert isomorphism == [("a", "n")]
  
      assert check_isomorphism(t1, t2, isomorphism)
  
file_path: networkx/networkx/algorithms/isomorphism/tests/test_tree_isomorphism.py
imports: import random
  import time
  import pytest
  import networkx
  from networkx.algorithms.isomorphism.tree_isomorphism import rooted_tree_isomorphism, tree_isomorphism
  from networkx.classes.function import is_directed
label_desc: Use image node_id 7 for calling a global function with example usage: test_trivial() without return types