code: def test_bias_predict_unknown_item():
      algo = Bias()
      algo.fit(simple_df)
  
      p = algo.predict_for_user(10, [1, 3, 4])
  
      assert len(p) == 3
      intended = algo.item_offsets_.loc[[1, 3]] + algo.mean_ + 0.25
      assert p.loc[[1, 3]].values == approx(intended.values)
      assert p.loc[4] == approx(algo.mean_ + 0.25)
  
imports: from lenskit.algorithms.bias import Bias
  from lenskit import util
  import logging
  import pickle
  import binpickle
  import pandas
  import numpy
  from pytest import approx, raises, mark
  from lenskit.util.test import ml_test
label_desc: Use image node_id 12 for calling a global function with example usage: test_bias_predict_unknown_item() without return types