code: def test_to_css(self) -> None:
      c = bcc.HSL(10, 0.2, 0.3)
      assert c.to_css() == "hsl(10, 20.0%, 30.0%)"
      c = bcc.HSL(10, 0.2, 0.3, 0.3)
      assert c.to_css() == "hsla(10, 20.0%, 30.0%, 0.3)"
  
imports: from __future__ import annotations
  import pytest
  import bokeh.colors.color
label_desc: Use image node_id 6 for calling the Test_HSL obj's underlying member method code with example usage: obj.test_to_css() without return types