code: def test_graph(self):
      G = nx.path_graph(4)
      H = node_link_graph(node_link_data(G))
      assert nx.is_isomorphic(G, H)
  
file_path: networkx/networkx/readwrite/json_graph/tests/test_node_link.py
imports: import json
  import pytest
  import networkx
  from networkx.readwrite.json_graph import node_link_data, node_link_graph
label_desc: Use image node_id 3 for calling the TestNodeLink obj's underlying member method code with example usage: obj.test_graph() without return types