code: def test_additional_items(self):
      with tempfile.TemporaryDirectory() as tempdir:
          with open(os.path.join(tempdir, "mask31.txt"), "w") as f:
              f.write("spleen31 mask")
  
          test_data = {
              "name": "Spleen",
              "description": "Spleen Segmentation",
              "labels": {"0": "background", "1": "spleen"},
              "training": [
                  {
                      "image": "spleen_19.nii.gz",
                      "label": "spleen_19.nii.gz",
                      "mask": "spleen mask",
                  },
                  {
                      "image": "spleen_31.nii.gz",
                      "label": "spleen_31.nii.gz",
                      "mask": "mask31.txt",
                  },
              ],
              "test": ["spleen_15.nii.gz", "spleen_23.nii.gz"],
          }
          json_str = json.dumps(test_data)
          file_path = os.path.join(tempdir, "test_data.json")
          with open(file_path, "w") as json_file:
              json_file.write(json_str)
          result = load_decathlon_datalist(
              file_path, True, "training", Path(tempdir)
          )
          self.assertEqual(
              result[0]["image"],
              os.path.join(tempdir, "spleen_19.nii.gz"),
          )
          self.assertEqual(
              result[0]["label"],
              os.path.join(tempdir, "spleen_19.nii.gz"),
          )
          self.assertEqual(
              result[1]["mask"], os.path.join(tempdir, "mask31.txt")
          )
          self.assertEqual(result[0]["mask"], "spleen mask")
  
file_path: MONAI/tests/test_load_decathlon_datalist.py
imports: from __future__ import annotations
  import json
  import os
  import tempfile
  import unittest
  from pathlib import Path
  from monai.data import load_decathlon_datalist
label_desc: Use image node_id 5 for calling the TestLoadDecathlonDatalist obj's underlying member method code with example usage: obj.test_additional_items() without return types