code: def test_open_csv() -> None:
      with patch("builtins.open") as mock_open:
          bus.open_csv("foo")
      assert mock_open.has_call(
          call("foo", "r", newline="", encoding="utf8")
      )
  
file_path: bokeh/tests/unit/bokeh/util/test_sampledata__util.py
imports: from __future__ import annotations
  import pytest
  from unittest.mock import call, patch
  import bokeh.util.sampledata
label_desc: Use image node_id 5 for calling a global function with example usage: test_open_csv() without return types