code: def nil() -> Doc:
      """An empty document."""
      return _nil
  
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 7 for calling a global function with example usage: nil() and returns: _nil