docstr: Test computation of xmarks data for single xmark.
  
          
docstr_tok: ["Test","computation","of","xmarks","data","for","single","xmark","."]
code: def test_get_xmarks_data(self):
      """Test computation of xmarks data for single xmark."""
  
      self.plot.xmarks = 1
      test_mark_data = dict(ys=[(1, 1)], xs=[(0.5, 0)])
      cmp_mark_data = self.plot._get_xmarks_data(["o1"], self.seg_bins)
  
      for sub_list in ["xs", "ys"]:
          test_pairs = zip(
              test_mark_data[sub_list], cmp_mark_data[sub_list]
          )
          for test_value, cmp_value in test_pairs:
              self.assertEqual(
                  np.array(test_value), np.array(cmp_value)
              )
  
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 12 for calling the BokehRadialHeatMapPlotTests obj's underlying member method code with example usage: obj.test_get_xmarks_data() without return types