docstr: Tests that the downsample works as expected.
docstr_tok: ["Tests","that","the","downsample","works","as","expected","."]
code: def test_downsample_preset(self, image_high, image_low):
      """Tests that the downsample works as expected."""
      downsample = lambda image: pyramid.downsample(image, num_levels=1)
      image_high = tf.expand_dims(
          tf.expand_dims(image_high, axis=-1), axis=0
      )
      image_low = tf.expand_dims(
          tf.expand_dims(image_low, axis=-1), axis=0
      )
  
      pyr = downsample(image_high)
  
      with self.subTest(name="image_high"):
          self.assertAllClose(image_high, pyr[0])
  
      with self.subTest(name="image_low"):
          self.assertAllClose(image_low, pyr[1])
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  from absl.testing import parameterized
  import numpy
  from six.moves import range
  import tensorflow
  from tensorflow_graphics.image import pyramid
  from tensorflow_graphics.util import test_case
label_desc: Use image node_id 4 for calling the PyramidTest obj's underlying member method code with example usage: obj.test_downsample_preset(image_high, image_low) without return types