def _get_nodes_by_instance(self, instance_uuid):
        try:
            node = objects.Node.get_by_instance_uuid(pecan.request.context,
                                                     instance_uuid)
            return [node]
        except exception.InstanceNotFound:
            return []
Tests that exactly N items in an iterable are "truthy" (neither None,
dataset/ETHPy150Open openstack/ironic/ironic/api/controllers/v1/node.py/NodesController._get_nodes_by_instance--crossover with--dataset/ETHPy150Open saltstack/salt/salt/utils/boto.py/exactly_n