docstr: Test if the bijector function works for additive coupling.
docstr_tok: ["Test","if","the","bijector","function","works","for","additive","coupling","."]
code: def testBijectorFn(self):
      """Test if the bijector function works for additive coupling."""
      ims = self._make_images()
  
      def shiftfn(input_shape):
          input_nchan = input_shape[-1]
          return tf_keras.Sequential(
              [
                  tf_keras.layers.Input(input_shape),
                  tf_keras.layers.Conv2D(
                      input_nchan, 3, padding="same"
                  ),
              ]
          )
  
      def shiftexitfn(input_shape, output_chan):
          return tf_keras.Sequential(
              [
                  tf_keras.layers.Input(input_shape),
                  tf_keras.layers.Conv2D(
                      output_chan, 3, padding="same"
                  ),
              ]
          )
  
      shiftonlyglow = glow.Glow(
          output_shape=self.output_shape,
          num_glow_blocks=2,
          num_steps_per_block=1,
          coupling_bijector_fn=shiftfn,
          exit_bijector_fn=shiftexitfn,
          grab_after_block=[0.5, 0.5],
      )
      z = shiftonlyglow.inverse(ims)
      self.evaluate([v.initializer for v in shiftonlyglow.variables])
      self.assertAllFinite(self.evaluate(z))
  
imports: import functools
  import numpy
  import tensorflow.compat.v2
  from tensorflow_probability.python.bijectors import bijector_test_util
  from tensorflow_probability.python.bijectors import blockwise
  from tensorflow_probability.python.bijectors import chain
  from tensorflow_probability.python.bijectors import composition
  from tensorflow_probability.python.bijectors import glow
  from tensorflow_probability.python.bijectors import identity
  from tensorflow_probability.python.bijectors import pad
  from tensorflow_probability.python.bijectors import sigmoid
  from tensorflow_probability.python.distributions import independent
  from tensorflow_probability.python.distributions import normal
  from tensorflow_probability.python.internal import test_util
  from tensorflow_probability.python.internal import tf_keras
  from tensorflow_probability.python.math.gradient import batch_jacobian
label_desc: Use image node_id 14 for calling the GlowTest obj's underlying member method code with example usage: obj.testBijectorFn() and returns: tf_keras, tf_keras