code: def test_window_size(self):
      sampler = ImageWindowGenerator(
          reader=get_2d_reader(), window_sizes=(0, 0, 0), batch_size=2
      )
      self.assert_tf_window(sampler)
      self.assert_window(sampler())
  
imports: from __future__ import absolute_import, print_function
  import os
  import unittest
  import numpy
  import tensorflow
  from niftynet.engine.image_window import N_SPATIAL, LOCATION_FORMAT
  from niftynet.engine.image_window_dataset import ImageWindowDataset
  from niftynet.io.image_reader import ImageReader
  from tests.niftynet_testcase import NiftyNetTestCase
label_desc: Use image node_id 5 for calling the ImageWindowDataset_Generator_2D_Test obj's underlying member method code with example usage: obj.test_window_size() without return types