code: def test_bars_color_index_color_clash(self):
      bars = Bars(
          [(0, 0, 0), (0, 1, 1), (0, 2, 2)], vdims=["y", "color"]
      ).opts(color="color", color_index="color")
      with ParamLogStream() as log:
          bokeh_renderer.get_plot(bars)
      log_msg = log.stream.read()
      warning = (
          "The `color_index` parameter is deprecated in favor of color style mapping, "
          "e.g. `color=dim('color')` or `line_color=dim('color')`\nCannot declare style "
          "mapping for 'color' option and declare a color_index; ignoring the color_index.\n"
      )
      self.assertEqual(log_msg, warning)
  
imports: import numpy
  from bokeh.models import CategoricalColorMapper, LinearAxis, LinearColorMapper
  from holoviews.core.overlay import NdOverlay, Overlay
  from holoviews.element import Bars
  from holoviews.plotting.bokeh.util import property_to_dict
  from ..utils import ParamLogStream
  from .test_plot import TestBokehPlot, bokeh_renderer
label_desc: Use image node_id 29 for calling the TestBarPlot obj's underlying member method code with example usage: obj.test_bars_color_index_color_clash() without return types