def _ancestors_or_self(
            self, qname: Union[QualName, bool] = None) -> List[InstanceNode]:
        """XPath - return the list of receiver's ancestors including itself."""
        res = [] if qname and self.qual_name != qname else [self]
        return res + self.up()._ancestors(qname)
XPath - return the list of receiver's ancestors including itself.