code: def test_null_visuals(self) -> None:
      kwargs = dict(fill_alpha=0.7, line_alpha=0.8, line_color="red")
      hover_visuals = None
      ca = bpr.make_glyph(Circle, kwargs, hover_visuals)
      assert ca is None
  
file_path: bokeh/tests/unit/bokeh/plotting/test__renderer.py
imports: from __future__ import annotations
  import pytest
  from bokeh.models import Circle
  import bokeh.plotting._renderer
label_desc: Use image node_id 1 for calling the Test_make_glyph obj's underlying member method code with example usage: obj.test_null_visuals() without return types