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
  
file_path: tensorflow-upstream/tensorflow/python/layers/utils.py
imports: from tensorflow.python.framework import smart_cond
  from tensorflow.python.ops import cond
  from tensorflow.python.ops import variables
label_desc: Use image node_id 4 for calling a global function with example usage: normalize_padding(value) and returns: padding