code: def test_content(self):
      with tempfile.TemporaryDirectory() as tempdir:
          datalist = []
          for i in range(5):
              image = os.path.join(tempdir, f"test_image{i}.nii.gz")
              label = os.path.join(tempdir, f"test_label{i}.nii.gz")
              Path(image).touch()
              Path(label).touch()
              datalist.append({"image": image, "label": label})
  
          filename = os.path.join(tempdir, "test_datalist.json")
          result = create_cross_validation_datalist(
              datalist=datalist,
              nfolds=5,
              train_folds=[0, 1, 2, 3],
              val_folds=4,
              train_key="test_train",
              val_key="test_val",
              filename=Path(filename),
              shuffle=True,
              seed=123,
              check_missing=True,
              keys=["image", "label"],
              root_dir=None,
              allow_missing_keys=False,
              raise_error=True,
          )
  
          loaded = load_decathlon_datalist(
              filename, data_list_key="test_train"
          )
          for r, l in zip(result["test_train"], loaded):
              self.assertEqual(r["image"], l["image"])
              self.assertEqual(r["label"], l["label"])
  
file_path: MONAI/tests/test_create_cross_validation_datalist.py
imports: from __future__ import annotations
  import os
  import tempfile
  import unittest
  from pathlib import Path
  from monai.data import create_cross_validation_datalist, load_decathlon_datalist
label_desc: Use image node_id 1 for calling the TestCreateCrossValidationDatalist obj's underlying member method code with example usage: obj.test_content() without return types