code: def test_init(self) -> None:
      with pytest.raises(TypeError):
          bcpn.Nullable()
      with pytest.raises(ValueError):
          bcpn.Nullable(Int(help="inner help"))
  
      prop0 = bcpn.Nullable(Int(), help="help")
      assert prop0._help == prop0.__doc__ == "help"
  
imports: from __future__ import annotations
  import pytest
  import warnings
  from typing import TYPE_CHECKING, Union
  from bokeh.core.properties import Dict, Instance, Int, List, String
  from bokeh.core.property.wrappers import PropertyValueDict, PropertyValueList
  from bokeh.util.warnings import BokehDeprecationWarning
  from tests.support.util.api import verify_all
  from _util_property import _TestHasProps, _TestModel
  import bokeh.core.property.nullable
label_desc: Use image node_id 1 for calling the Test_Nullable obj's underlying member method code with example usage: obj.test_init() without return types