code: def _random_string(length):
      return bytes(
          "".join(random.choices(string.ascii_lowercase, k=length)),
          encoding="utf-8",
      )
  
imports: import os
  import random
  import string
  import riegeli
  from tensorflow.python.platform import test
  from tensorflow.tools.proto_splitter import chunk_pb2
  from tensorflow.tools.proto_splitter import split
  from tensorflow.tools.proto_splitter.testdata import test_message_pb2
label_desc: Use image node_id 1 for calling a global function with example usage: _random_string(length) and returns: bytes