code: def on_update(self, value, *args, **kwargs):
          
          parent_value = self._parent_min
          if self._max != self._min:
              sub_progress = (value - self._min) / (self._max - self._min)
              parent_value = self._parent_min + sub_progress * (self._parent_max - self._parent_min)
          self._parent.update(parent_value, *args, **kwargs)
docs: Inform the parent of progress.
          :param value: The value of this subprogresscallback
          :param args: Extra positional arguments
          :param kwargs: Extra keyword arguments