code: def test_sim_users(sim_users):
      assert sim_users.shape == (5, 2)
  
file_path: recommenders/tests/unit/recommenders/models/test_lightfm_utils.py
imports: import pytest
  import itertools
  import numpy
  import pandas
  from lightfm.data import Dataset
  from lightfm import LightFM, cross_validation
  from recommenders.models.lightfm.lightfm_utils import track_model_metrics, similar_users, similar_items
label_desc: Use image node_id 9 for calling a global function with example usage: test_sim_users(sim_users) without return types