code: def test__apply_transorm(self):
      I = np.ones((2, 2))
      A = I * 0
      B = I * 1
      C = I * 2
      D = I * 3
      image = np.block([[A, B], [C, D]])
      with patch(
          "ISR.utils.datahandler.DataHandler._make_img_list",
          return_value=True,
      ):
          with patch(
              "ISR.utils.datahandler.DataHandler._check_dataset",
              return_value=True,
          ):
              DH = DataHandler(
                  lr_dir=None,
                  hr_dir=None,
                  patch_size=3,
                  scale=2,
                  n_validation_samples=None,
              )
      transf = [[1, 0], [0, 1], [2, 0], [0, 2], [1, 1], [0, 0]]
      self.assertTrue(
          np.all(
              np.block([[C, A], [D, B]])
              == DH._apply_transform(image, transf[0])
          )
      )
      self.assertTrue(
          np.all(
              np.block([[C, D], [A, B]])
              == DH._apply_transform(image, transf[1])
          )
      )
      self.assertTrue(
          np.all(
              np.block([[B, D], [A, C]])
              == DH._apply_transform(image, transf[2])
          )
      )
      self.assertTrue(
          np.all(
              np.block([[B, A], [D, C]])
              == DH._apply_transform(image, transf[3])
          )
      )
      self.assertTrue(
          np.all(
              np.block([[D, B], [C, A]])
              == DH._apply_transform(image, transf[4])
          )
      )
      self.assertTrue(
          np.all(image == DH._apply_transform(image, transf[5]))
      )
  
imports: import unittest
  import numpy
  from unittest.mock import patch
  from ISR.utils.datahandler import DataHandler
label_desc: Use image node_id 13 for calling the DataHandlerTest obj's underlying member method code with example usage: obj.test__apply_transorm() without return types