code: def test_str(self) -> None:
      prop = bcpr.Required(List(Int))
      assert str(prop) == "Required(List(Int))"
  
file_path: bokeh/tests/unit/bokeh/core/property/test_required.py
imports: from __future__ import annotations
  import pytest
  from bokeh.core.properties import Instance, Int, List
  from tests.support.util.api import verify_all
  from _util_property import _TestHasProps, _TestModel
  import bokeh.core.property.required
label_desc: Use image node_id 5 for calling the Test_Required obj's underlying member method code with example usage: obj.test_str() without return types