code: def _get_ann_labels_data(self, order_ann, bins_ann):
          
  
          if self.yticks is None:
              return dict(x=[], y=[], text=[], angle=[])
  
          mapping = self._compute_tick_mapping("radius", order_ann, bins_ann)
          values = [(label, radius[0]) for label, radius in mapping.items()]
  
          labels, radius = zip(*values)
          radius = np.array(radius)
  
          y_coord = np.sin(np.deg2rad(self.yrotation)) * radius + self.max_radius
          x_coord = np.cos(np.deg2rad(self.yrotation)) * radius + self.max_radius
  
          return dict(x=x_coord,
                      y=y_coord,
                      text=labels,
                      angle=[0]*len(labels))
docs: Generate ColumnDataSource dictionary for annular labels.