code: def make_root_tuple_info(stream_id, tuple_id):
      
      key = random.getrandbits(TupleHelper.MAX_SFIXED64_RAND_BITS)
      return RootTupleInfo(stream_id=stream_id, tuple_id=tuple_id,
                           insertion_time=time.time(), key=key)
docs: Creates a RootTupleInfo