code: def test_recall_empty_zero():
      prec = _test_recall([], [1, 3])
      assert prec == approx(0)
  
file_path: lkpy/tests/test_topn_recall.py
imports: import logging
  import numpy
  import pandas
  from pytest import approx
  from lenskit.metrics.topn import recall
  from lenskit.util.test import demo_recs
  from lenskit import topn
label_desc: Use image node_id 2 for calling a global function with example usage: test_recall_empty_zero() without return types