code: def test_invalid(self) -> None:
      prop = bcpr.Required(List(Int))
  
      assert not prop.is_valid(None)
  
      assert not prop.is_valid(-100)
      assert not prop.is_valid("yyy")
      assert not prop.is_valid([1, 2, ""])
  
      assert not prop.is_valid(())
      assert not prop.is_valid({})
      assert not prop.is_valid(_TestHasProps())
      assert not prop.is_valid(_TestModel())
  
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 3 for calling the Test_Required obj's underlying member method code with example usage: obj.test_invalid() without return types