code: def check_retrieval_twice(
      self, train_name, test_name, root, retrieval_func, package
  ):
      self.cached_train_file = os.path.join(root, train_name)
      self.cached_test_file = os.path.join(root, test_name)
      train, test = retrieval_func(
          withlabel=self.withlabel,
          ndim=self.ndim,
          scale=self.scale,
          rgb_format=self.rgb_format,
      )
  
      numpy = importlib.import_module("numpy", package=package)
      with mock.patch.object(
          numpy, "savez_compressed"
      ) as savez_compressed:
          with mock.patch.object(
              numpy, "load", wraps=numpy.load
          ) as load:
              train, test = retrieval_func(
                  withlabel=self.withlabel,
                  ndim=self.ndim,
                  scale=self.scale,
                  rgb_format=self.rgb_format,
              )
      savez_compressed.assert_not_called()  # creator() not called
      self.assertEqual(load.call_count, 2)
  
imports: import importlib
  import os
  import unittest
  import mock
  import numpy
  from chainer.dataset import download
  from chainer.datasets import get_fashion_mnist
  from chainer.datasets import get_fashion_mnist_labels
  from chainer.datasets import get_kuzushiji_mnist
  from chainer.datasets import get_kuzushiji_mnist_labels
  from chainer.datasets import get_mnist
  from chainer.datasets import tuple_dataset
  from chainer import testing
  from chainer.testing import attr
label_desc: Use image node_id 12 for calling the TestMnist obj's underlying member method code with example usage: obj.check_retrieval_twice(train_name, test_name, root, retrieval_func, package) without return types