code: def test_radial_heatmap_colorbar(self):
      hm = HeatMap([(0, 0, 1), (0, 1, 2), (1, 0, 3)]).opts(
          radial=True, colorbar=True
      )
      plot = bokeh_renderer.get_plot(hm)
      self.assertIsInstance(plot.handles.get("colorbar"), ColorBar)
  
imports: from itertools import product
  import numpy
  from bokeh.models import ColorBar
  from holoviews.core.spaces import HoloMap
  from holoviews.element.raster import HeatMap
  from holoviews.plotting.bokeh import RadialHeatMapPlot
  from .test_plot import TestBokehPlot, bokeh_renderer
label_desc: Use image node_id 17 for calling the BokehRadialHeatMapPlotTests obj's underlying member method code with example usage: obj.test_radial_heatmap_colorbar() without return types