code: def _compute(self):
          
          for serie in self.series:
              serie.points, serie.outliers = \
                  self._box_points(serie.values, self.box_mode)
  
          self._x_pos = [(i + .5) / self._order for i in range(self._order)]
  
          if self._min:
              self._box.ymin = min(self._min, self.zero)
          if self._max:
              self._box.ymax = max(self._max, self.zero)
docs: Compute parameters necessary for later steps
          within the rendering process