code: def test_hit_norel_na():
      hr = _test_hit([1, 3], [])
      assert hr is None
  
file_path: lkpy/tests/test_topn_hit.py
imports: import logging
  import numpy
  import pandas
  from pytest import approx
  from lenskit.metrics.topn import hit
  from lenskit.util.test import demo_recs
  from lenskit import topn
label_desc: Use image node_id 3 for calling a global function with example usage: test_hit_norel_na() without return types