code: def __add__(self, other: Doc) -> Doc:
      return concat([self, other])
  
imports: from __future__ import annotations
  import abc
  from collections.abc import Sequence
  import enum
  from functools import partial
  import sys
  from typing import NamedTuple
  from jax._src import config
label_desc: Use image node_id 3 for calling the Doc obj's underlying member method code with example usage: obj.__add__(other) and returns: concat