code: def test_3d_avg_shape(self):
      input_param = {
          "func": "AVG",
          "kernel_size": [3, 3, 2],
          "stride": [3, 2, 1],
      }
      self._test_nd_downsample_output_shape(
          rank=3, param_dict=input_param, output_shape=(2, 6, 8, 16, 8)
      )
  
file_path: NiftyNet/tests/downsample_test.py
imports: from __future__ import absolute_import, print_function
  import tensorflow
  from niftynet.layer.downsample import DownSampleLayer
  from tests.niftynet_testcase import NiftyNetTestCase
label_desc: Use image node_id 5 for calling the DownSampleTest obj's underlying member method code with example usage: obj.test_3d_avg_shape() without return types