code: def test__make_img_list_validation(self):
      with patch("os.listdir", side_effect=self.fake_folders):
          with patch(
              "ISR.utils.datahandler.DataHandler._check_dataset",
              return_value=True,
          ):
              with patch(
                  "numpy.random.choice", return_value=np.array([0])
              ):
                  DH = DataHandler(
                      lr_dir={"res": "lr", "matching": False},
                      hr_dir={"res": "hr", "matching": False},
                      patch_size=0,
                      scale=0,
                      n_validation_samples=10,
                  )
  
      expected_ls = {"hr": ["data0.jpeg"], "lr": ["data1.png"]}
      self.assertTrue(np.all(DH.img_list["hr"] == expected_ls["hr"]))
      self.assertTrue(np.all(DH.img_list["lr"] == expected_ls["lr"]))
  
imports: import unittest
  import numpy
  from unittest.mock import patch
  from ISR.utils.datahandler import DataHandler
label_desc: Use image node_id 7 for calling the DataHandlerTest obj's underlying member method code with example usage: obj.test__make_img_list_validation() without return types