code: def get_2d_input(self):
      input_shape = (2, 16, 16, 8)
      x = tf.ones(input_shape)
      return x
  
file_path: NiftyNet/tests/downsample_res_block_test.py
imports: from __future__ import absolute_import, print_function
  import tensorflow
  from niftynet.layer.downsample_res_block import DownBlock
  from tests.niftynet_testcase import NiftyNetTestCase
label_desc: Use image node_id 2 for calling the DownsampleResBlockTest obj's underlying member method code with example usage: obj.get_2d_input() and returns: x