code: def test_invalid_folds(n_splits):
      X, y = get_x_y(n_samples=1000, n_classes=2)
  
      err_msg = f"n_splits {n_splits} is not a integer at least 2"
      with pytest.raises(ValueError, match=err_msg):
          kf = StratifiedKFold(n_splits=n_splits)
          for train_index, test_index in kf.split(X, y):
              break
  
imports: from cuml.model_selection import StratifiedKFold
  import pytest
  from cuml.internals.safe_imports import gpu_only_import
label_desc: Use image node_id 4 for calling a global function with example usage: test_invalid_folds(n_splits) without return types