code: def _map_key_proto(key_type, key):
      """Returns MapKey proto for a key of key_type."""
      return _MAP_KEY[key_type](key)
  
file_path: tensorflow/tensorflow/tools/proto_splitter/util.py
imports: from collections.abc import Sequence
  from typing import Any, Optional, Union
  from google.protobuf import descriptor
  from google.protobuf import message
  from tensorflow.tools.proto_splitter import chunk_pb2
label_desc: Use image node_id 7 for calling a global function with example usage: _map_key_proto(key_type, key) and returns: _MAP_KEY