code: def test_bad_ws(self) -> None:
      with pytest.raises(ValueError):
          bes._clean_url("ws://foo")
  
imports: from __future__ import annotations
  import pytest
  import bs4
  import bokeh.embed.server
label_desc: Use image node_id 2 for calling the Test__clean_url obj's underlying member method code with example usage: obj.test_bad_ws() without return types