def queryset(self, request, queryset):
        """
        Returns the filtered queryset based on the value
        provided in the query string and retrievable via
        `self.value()`.
        """
        if self.value():
            try:
                section = SectionPage.objects.get(id=self.value())
                return queryset.child_of(section).all()
            except (ObjectDoesNotExist, MultipleObjectsReturned):
                return None
Returns the filtered queryset based on the value
        provided in the query string and retrievable via
        `self.value()`.