code: def test_cs_rated_items_series():
      "rated_items should de-index series"
      items = ["a", "b", "wombat"]
      series = pd.Series(np.random.randn(3), index=items)
  
      i2 = CandidateSelector.rated_items(series)
      assert isinstance(i2, np.ndarray)
      assert all(i2 == items)
  
imports: from lenskit.algorithms import CandidateSelector
  import pandas
  import numpy
label_desc: Use image node_id 1 for calling a global function with example usage: test_cs_rated_items_series() without return types