code: def test_bad_font_size_values(self) -> None:
      class Foo(HasProps):
          x = bcpd.FontSizeSpec(default="0px")
  
      a = Foo()
  
      with pytest.raises(ValueError):
          a.x = "6"
  
      with pytest.raises(ValueError):
          a.x = 6
  
      with pytest.raises(ValueError):
          a.x = ""
  
imports: from __future__ import annotations
  import pytest
  import datetime
  import warnings
  from copy import copy
  import numpy
  import pandas
  from bokeh.core.has_props import HasProps, Local
  from bokeh.core.property.vectorization import Field, Value, field, value
  from tests.support.util.api import verify_all
  import bokeh.core.property.dataspec
label_desc: Use image node_id 2 for calling the Test_FontSizeSpec obj's underlying member method code with example usage: obj.test_bad_font_size_values() without return types