code: def test_Undefined() -> None:
      assert (bcpu.Undefined == bcpu.Undefined) is True
      assert (bcpu.Undefined != bcpu.Undefined) is False
      assert (bcpu.Undefined is bcpu.Undefined) is True
      assert (bcpu.Undefined is not bcpu.Undefined) is False
      assert (copy(bcpu.Undefined) is bcpu.Undefined) is True
      assert (copy(bcpu.Undefined) is not bcpu.Undefined) is False
  
imports: from __future__ import annotations
  import pytest
  from copy import copy
  import bokeh.core.property.singletons
label_desc: Use image node_id 1 for calling a global function with example usage: test_Undefined() without return types