def _rel_ref_count(self, rId):
        rIds = self._element.xpath('//@r:id')
        return len([_rId for _rId in rIds if _rId == rId])
List nodes from cluster.
dataset/ETHPy150Open scanny/python-pptx/pptx/opc/package.py/Part._rel_ref_count--crossover with--dataset/ETHPy150Open openstack/python-senlinclient/senlinclient/v1/shell.py/do_cluster_node_list