code: def test_bad_proto(self) -> None:
      with pytest.raises(ValueError):
          bcu.server_url_for_websocket_url("junk://foo.com/ws")
  
file_path: bokeh/tests/unit/bokeh/client/test_util__client.py
imports: from __future__ import annotations
  import pytest
  import bokeh.client.util
label_desc: Use image node_id 3 for calling the Test_server_url_for_websocket_url obj's underlying member method code with example usage: obj.test_bad_proto() without return types