code: def test_symmetrize_unweighted(graph_file):
      gc.collect()
  
      cu_M = graph_file.get_edgelist()
      sym_sources, sym_destinations = cugraph.symmetrize(
          cu_M["src"], cu_M["dst"]
      )
  
      #
      #  Check to see if all pairs in sources/destinations exist in
      #  both directions
      #
      compare(
          cu_M["src"],
          cu_M["dst"],
          None,
          sym_sources,
          sym_destinations,
          None,
      )
  
file_path: cugraph/python/cugraph/cugraph/tests/internals/test_symmetrize.py
imports: import gc
  import pytest
  import pandas
  import cudf
  import cugraph
  from cugraph.testing import DEFAULT_DATASETS
label_desc: Use image node_id 3 for calling a global function with example usage: test_symmetrize_unweighted(graph_file) without return types