docstr: Test correct computation of a single segment label data point.
  
          
docstr_tok: ["Test","correct","computation","of","a","single","segment","label","data","point","."]
code: def test_get_seg_labels_data(self):
      """Test correct computation of a single segment label data point."""
  
      radiant = np.pi / 2
      x = np.cos(radiant) + 1
      y = np.sin(radiant) + 1
      angle = 1.5 * np.pi + radiant
  
      test_seg_data = dict(
          x=np.array(x),
          y=np.array(y),
          text=np.array("o1"),
          angle=np.array(angle),
      )
  
      cmp_seg_data = self.plot._get_seg_labels_data(
          ["o1"], self.seg_bins
      )
  
      self.assertEqual(test_seg_data, cmp_seg_data)
  
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 9 for calling the BokehRadialHeatMapPlotTests obj's underlying member method code with example usage: obj.test_get_seg_labels_data() without return types