code: def test_shape(self, transform, expected_shape):
      test_image = nib.Nifti1Image(
          np.random.randint(0, 2, size=[128, 128, 128]).astype(float),
          np.eye(4),
      )
      with tempfile.TemporaryDirectory() as tempdir:
          nib.save(
              test_image, os.path.join(tempdir, "test_image1.nii.gz")
          )
          nib.save(
              test_image, os.path.join(tempdir, "test_label1.nii.gz")
          )
          nib.save(
              test_image, os.path.join(tempdir, "test_extra1.nii.gz")
          )
          nib.save(
              test_image, os.path.join(tempdir, "test_image2.nii.gz")
          )
          nib.save(
              test_image, os.path.join(tempdir, "test_label2.nii.gz")
          )
          nib.save(
              test_image, os.path.join(tempdir, "test_extra2.nii.gz")
          )
          test_data = [
              {
                  "image": os.path.join(tempdir, "test_image1.nii.gz"),
                  "label": os.path.join(tempdir, "test_label1.nii.gz"),
                  "extra": os.path.join(tempdir, "test_extra1.nii.gz"),
              },
              {
                  "image": os.path.join(tempdir, "test_image2.nii.gz"),
                  "label": os.path.join(tempdir, "test_label2.nii.gz"),
                  "extra": os.path.join(tempdir, "test_extra2.nii.gz"),
              },
          ]
  
          cache_dir = os.path.join(
              os.path.join(tempdir, "cache"), "data"
          )
          dataset_precached = GDSDataset(
              data=test_data,
              transform=transform,
              cache_dir=cache_dir,
              device=0,
          )
          data1_precached = dataset_precached[0]
          data2_precached = dataset_precached[1]
  
          dataset_postcached = GDSDataset(
              data=test_data,
              transform=transform,
              cache_dir=cache_dir,
              device=0,
          )
          data1_postcached = dataset_postcached[0]
          data2_postcached = dataset_postcached[1]
          data3_postcached = dataset_postcached[0:2]
  
          if transform is None:
              self.assertEqual(
                  data1_precached["image"],
                  os.path.join(tempdir, "test_image1.nii.gz"),
              )
              self.assertEqual(
                  data2_precached["label"],
                  os.path.join(tempdir, "test_label2.nii.gz"),
              )
              self.assertEqual(
                  data1_postcached["image"],
                  os.path.join(tempdir, "test_image1.nii.gz"),
              )
              self.assertEqual(
                  data2_postcached["extra"],
                  os.path.join(tempdir, "test_extra2.nii.gz"),
              )
          else:
              self.assertTupleEqual(
                  data1_precached["image"].shape, expected_shape
              )
              self.assertTupleEqual(
                  data1_precached["label"].shape, expected_shape
              )
              self.assertTupleEqual(
                  data1_precached["extra"].shape, expected_shape
              )
              self.assertTupleEqual(
                  data2_precached["image"].shape, expected_shape
              )
              self.assertTupleEqual(
                  data2_precached["label"].shape, expected_shape
              )
              self.assertTupleEqual(
                  data2_precached["extra"].shape, expected_shape
              )
  
              self.assertTupleEqual(
                  data1_postcached["image"].shape, expected_shape
              )
              self.assertTupleEqual(
                  data1_postcached["label"].shape, expected_shape
              )
              self.assertTupleEqual(
                  data1_postcached["extra"].shape, expected_shape
              )
              self.assertTupleEqual(
                  data2_postcached["image"].shape, expected_shape
              )
              self.assertTupleEqual(
                  data2_postcached["label"].shape, expected_shape
              )
              self.assertTupleEqual(
                  data2_postcached["extra"].shape, expected_shape
              )
              for d in data3_postcached:
                  self.assertTupleEqual(
                      d["image"].shape, expected_shape
                  )
  
          # update the data to cache
          test_data_new = [
              {
                  "image": os.path.join(
                      tempdir, "test_image1_new.nii.gz"
                  ),
                  "label": os.path.join(
                      tempdir, "test_label1_new.nii.gz"
                  ),
                  "extra": os.path.join(
                      tempdir, "test_extra1_new.nii.gz"
                  ),
              },
              {
                  "image": os.path.join(
                      tempdir, "test_image2_new.nii.gz"
                  ),
                  "label": os.path.join(
                      tempdir, "test_label2_new.nii.gz"
                  ),
                  "extra": os.path.join(
                      tempdir, "test_extra2_new.nii.gz"
                  ),
              },
          ]
          dataset_postcached.set_data(data=test_data_new)
          # test new exchanged cache content
          if transform is None:
              self.assertEqual(
                  dataset_postcached[0]["image"],
                  os.path.join(tempdir, "test_image1_new.nii.gz"),
              )
              self.assertEqual(
                  dataset_postcached[0]["label"],
                  os.path.join(tempdir, "test_label1_new.nii.gz"),
              )
              self.assertEqual(
                  dataset_postcached[1]["extra"],
                  os.path.join(tempdir, "test_extra2_new.nii.gz"),
              )
  
imports: from __future__ import annotations
  import os
  import pickle
  import tempfile
  import unittest
  import numpy
  import torch
  from parameterized import parameterized
  from monai.data import GDSDataset, json_hashing
  from monai.transforms import Compose, Flip, Identity, LoadImaged, SimulateDelayd, Transform
  from monai.utils import optional_import
  from tests.utils import TEST_NDARRAYS, assert_allclose
label_desc: Use image node_id 4 for calling the TestDataset obj's underlying member method code with example usage: obj.test_shape(transform, expected_shape) without return types