old_contents: import random
  from ..typecheck import type_hints
  from typing import final
  
  
  @final
  class UID(object):
      """A unique id"""
  
      def __init__(self):
          self.value = random.getrandbits(32)
  
new_contents: import uuid
  from ..typecheck import type_hints
  from typing import final
  
  
  @final
  class UID(object):
      """A unique id"""
  
      def __init__(self):
          # TODO find out what type is smaller for protobuf msgs.
          self.value = str(uuid.UUID(int=0x12345678123456781234567812345678))
  
subject: use python uuid instead of random int for object ids (#3868)