code: def test_2d_1d(self):
      aff = tf.constant([[1.5, 2, 3, 2, 1.5, 4]], dtype=tf.float32)
      params = {"source_shape": (3, 3), "output_shape": (2,)}
      expected = [[[0.5, 1.5], [3.5, 5.5]]]
      self._test_correctness(params, aff, expected)
  
imports: from __future__ import absolute_import, print_function, division
  import numpy
  import tensorflow
  from niftynet.layer.grid_warper import AffineGridWarperLayer
  from niftynet.layer.grid_warper import AffineWarpConstraints
  from niftynet.layer.grid_warper import _create_affine_features
  from tests.niftynet_testcase import NiftyNetTestCase
label_desc: Use image node_id 7 for calling the AffineGridWarperLayerTest obj's underlying member method code with example usage: obj.test_2d_1d() without return types