code: def normalize_padding(value):
      padding = value.lower()
      if padding not in {"valid", "same"}:
          raise ValueError(
              'The `padding` argument must be one of "valid", "same". '
              f"Received: {str(padding)}."
          )
      return padding
  
imports: import tensorflow.compat.v2
  from tensorflow_probability.python import random
  from tensorflow_probability.python.distributions import independent
  from tensorflow_probability.python.distributions import kullback_leibler
  from tensorflow_probability.python.distributions import normal
  from tensorflow_probability.python.internal import docstring_util
  from tensorflow_probability.python.internal import tf_keras
  from tensorflow_probability.python.layers import util
  from tensorflow_probability.python.util.seed_stream import SeedStream
  from tensorflow.python.ops import nn_ops
label_desc: Use image node_id 4 for calling a global function with example usage: normalize_padding(value) and returns: padding