code: def test_nested_dict():
      val = {i: "b" * 100 for i in range(10)}
      val[0] = val
      deserialized = deserialize(*serialize(val))
      assert deserialized[0] is deserialized
  
      val = KeyedDict(abcd="efgh")
      val[val] = val
      deserialized = deserialize(*serialize(val))
      assert deserialized[val] is deserialized
  
imports: import threading
  from collections import defaultdict, OrderedDict
  from typing import Any, Dict, List, Tuple
  import numpy
  import pandas
  import pytest
  from ...lib.sparse import SparseMatrix
  from ...tests.core import require_cupy, require_cudf
  from ...utils import lazy_import
  from ..None import serialize, serialize_with_spawn, deserialize
  from ..core import Placeholder, ListSerializer
label_desc: Use image node_id 5 for calling a global function with example usage: test_nested_dict() without return types