code: def _compute_box(self, positive_vals, negative_vals):
          
          max_ = max(
              max(positive_vals or [self.zero]),
              max(negative_vals or [self.zero])
          )
  
          if self.range and self.range[0] is not None:
              self._box.ymin = self.range[0]
          else:
              self._box.ymin = -max_
  
          if self.range and self.range[1] is not None:
              self._box.ymax = self.range[1]
          else:
              self._box.ymax = max_
docs: Compute Y min and max