code: def test_kfold_balance(setup):
      # Check that KFold returns folds with balanced sizes
      for i in range(11, 17):
          kf = KFold(5).split(X=np.ones(i))
          sizes = [len(test) for _, test in kf]
  
          assert (np.max(sizes) - np.min(sizes)) <= 1
          assert np.sum(sizes) == i
  
imports: import itertools
  import numpy
  import pandas
  import pytest
  from ....None import dataframe
  from ....None import tensor
  from ....dataframe.core import DATAFRAME_TYPE
  from ....lib.sparse import SparseNDArray
  from ...utils.validation import _num_samples
  from ..None import train_test_split, KFold
label_desc: Use image node_id 14 for calling a global function with example usage: test_kfold_balance(setup) without return types