code: def test_pickle():
      for (
          name,
          func,
      ) in nx.utils.backends._registered_algorithms.items():
          assert pickle.loads(pickle.dumps(func)) is func
      assert (
          pickle.loads(pickle.dumps(nx.inverse_line_graph))
          is nx.inverse_line_graph
      )
  
imports: import pickle
  import pytest
  import networkx
label_desc: Use image node_id 2 for calling a global function with example usage: test_pickle() without return types