code: def test_ohlc_hover_cols_all():
      plot = df.hvplot.ohlc(y=ohlc_cols, hover_cols="all")
      segments = plot.Segments.I
      assert "Volume" in segments
      tooltips = segments.opts.get("plot").kwargs["tools"][0].tooltips
      assert len(tooltips) == len(df.columns) + 1
      assert tooltips[-1] == ("Volume", "@Volume")
  
label_desc: Use image node_id 2 for calling a global function with example usage: test_ohlc_hover_cols_all() without return types