code: def get_extents(self, element, ranges, range_type='combined'):
          
          xdim, ydim = element.nodes.kdims[:2]
          if range_type not in ('combined', 'data', 'extents'):
              return xdim.range[0], ydim.range[0], xdim.range[1], ydim.range[1]
          no_labels = (element.nodes.get_dimension(self.label_index) is None and
                       self.labels is None)
          rng = 1.1 if no_labels else 1.4
          x0, x1 = max_range([xdim.range, (-rng, rng)])
          y0, y1 = max_range([ydim.range, (-rng, rng)])
          return (x0, y0, x1, y1)
docs: A Chord plot is always drawn on a unit circle.