code: def test_close_early(self):
      sampler = BalancedSampler(
          reader=get_2d_reader(),
          window_sizes=MOD_2D_DATA,
          batch_size=2,
          windows_per_image=10,
          queue_length=10,
      )
      sampler.close_all()
  
imports: from __future__ import absolute_import, division, print_function
  import os
  import unittest
  import numpy
  import tensorflow
  from niftynet.engine.image_window import N_SPATIAL
  from niftynet.engine.sampler_balanced_v2 import BalancedSampler, balanced_spatial_coordinates
  from niftynet.io.image_reader import ImageReader
  from niftynet.io.image_sets_partitioner import ImageSetsPartitioner
  from niftynet.utilities.util_common import ParserNamespace
  from tests.niftynet_testcase import NiftyNetTestCase
label_desc: Use image node_id 5 for calling the BalancedSamplerTest obj's underlying member method code with example usage: obj.test_close_early() without return types