code: def test_placeholder_obj():
      assert Placeholder(1024) == Placeholder(1024)
      assert hash(Placeholder(1024)) == hash(Placeholder(1024))
      assert Placeholder(1024) != Placeholder(1023)
      assert hash(Placeholder(1024)) != hash(Placeholder(1023))
      assert Placeholder(1024) != 1024
      assert "1024" in repr(Placeholder(1024))
  
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 3 for calling a global function with example usage: test_placeholder_obj() without return types