code: def test_relabel_nodes_callable_type(self):
      G = nx.path_graph(4)
      H = nx.relabel_nodes(G, str)
      assert nodes_equal(H.nodes, ["0", "1", "2", "3"])
  
imports: import pytest
  import networkx
  from networkx.generators.classic import empty_graph
  from networkx.utils import edges_equal, nodes_equal
label_desc: Use image node_id 6 for calling the TestRelabel obj's underlying member method code with example usage: obj.test_relabel_nodes_callable_type() without return types