def hook_get_results(self, changelist):
        """Triggered by `ChangeList.get_results()`."""

        # Poor NestedSet guys they've punished themselves once chosen that approach,
        # and now we punish them again with all those DB hits.

        result_list = list(changelist.result_list)

        # Get children stats.
        filter_kwargs = {'%s' % self.left_field: models.F('%s' % self.right_field) - 1}  # Leaf nodes only.
        filter_kwargs.update(self.get_immediate_children_filter(self.parent))

        stats_qs = changelist.result_list.filter(**filter_kwargs).values_list('id')
        leafs = [item[0] for item in stats_qs]

        for result in result_list:

            if result.id in leafs:
                setattr(result, self.CHILD_COUNT_MODEL_ATTR, 0)
            else:
                setattr(result, self.CHILD_COUNT_MODEL_ATTR, '>1')  # Too much pain to get real stats, so that'll suffice.

        if self.pid:
            # Render to upper level link.
            parent = self.parent

            filter_kwargs = {
                '%s__lt' % self.left_field: getattr(parent, self.left_field),
                '%s__gt' % self.right_field: getattr(parent, self.right_field),
            }

            try:
                granparent_id = changelist.model.objects.filter(**filter_kwargs).order_by('-%s' % self.left_field)[0].id
            except IndexError:
                granparent_id = None

            if granparent_id != parent.id:
                parent = changelist.model(pk=granparent_id)

            setattr(parent, self.UPPER_LEVEL_MODEL_ATTR, True)
            result_list = [parent] + result_list

        changelist.result_list = result_list