code: def noise_op(latents, hparams):
      """Adds isotropic gaussian-noise to each latent.
  
      Args:
        latents: 4-D or 5-D tensor, shape=(NTHWC) or (NHWC).
        hparams: HParams.
      Returns:
        latents: latents with isotropic gaussian noise appended.
      """
      if (
          hparams.latent_noise == 0
          or hparams.mode != tf_estimator.ModeKeys.TRAIN
      ):
          return latents
      latent_shape = common_layers.shape_list(latents)
      return latents + tf.random_normal(
          latent_shape, stddev=hparams.latent_noise
      )
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import functools
  import numpy
  import scipy
  from tensor2tensor.layers import common_layers
  from tensor2tensor.layers import common_video
  from tensor2tensor.utils import contrib
  import tensorflow.compat.v1
  from tensorflow.compat.v1 import estimator
  import tensorflow_probability
label_desc: Use image node_id 30 for calling a global function with example usage: noise_op(latents, hparams) and returns: unknown, latents