code: def test_fetch(self):
      xnat = XNATDatastorMocked(
          "http://xnat.com",
          cache_path=os.path.join(base_dir, "data", "xnat_cache"),
      )
      xnat.get_image_info("abcd/xyz/1234/def")
      xnat.get_image("abcd/xyz/1234/def")
      xnat.list_images()
  
file_path: MONAILabel/tests/unit/datastore/test_xnat.py
imports: import argparse
  import os
  import unittest
  from monailabel.datastore.xnat import XNATDatastore
label_desc: Use image node_id 1 for calling the TestXNAT obj's underlying member method code with example usage: obj.test_fetch() without return types