code: def test_cross_validation(xseq, yseq):
      crf = CRF()
      X = [xseq] * 20
      y = [yseq] * 20
      scores = cross_val_score(crf, X, y, n_jobs=5, cv=5)
      assert scores.mean() == 1.0
  
file_path: sklearn-crfsuite/tests/test_crf.py
imports: import os
  import pickle
  import pytest
  from sklearn.model_selection import cross_val_score
  from sklearn_crfsuite import CRF
label_desc: Use image node_id 8 for calling a global function with example usage: test_cross_validation(xseq, yseq) without return types