def create_node(
            self, api=False,
            exclude=None, expect_http=201,
            expected_error=None,
            **kwargs):
        # TODO(alekseyk) Simplify 'interfaces' and 'mac' manipulation logic
        metadata = kwargs.get('meta', {})
        default_metadata = self.default_metadata()
        default_metadata.update(metadata)

        mac = kwargs.get('mac', self.generate_random_mac())
        if default_metadata['interfaces']:
            if not metadata or 'interfaces' not in metadata:
                default_metadata['interfaces'][0]['mac'] = mac
                default_metadata['interfaces'][0]['pxe'] = True
                for iface in default_metadata['interfaces'][1:]:
                    if 'mac' in iface:
                        iface['mac'] = self.generate_random_mac()
            else:
                for iface in default_metadata['interfaces']:
                    if iface.get('pxe'):
                        if not iface.get('mac'):
                            iface['mac'] = mac
                        elif 'mac' not in kwargs:
                            mac = iface['mac']
                    if iface.get('mac') == mac:
                        break
                else:
                    default_metadata['interfaces'][0]['mac'] = mac
                    default_metadata['interfaces'][0]['pxe'] = True

        node_data = {
            'mac': mac,
            'status': 'discover',
            'ip': '10.20.0.130',
            'meta': default_metadata
        }
        if kwargs:
            meta = kwargs.pop('meta', None)
            node_data.update(kwargs)
            if meta:
                kwargs['meta'] = meta

        if exclude and isinstance(exclude, list):
            for ex in exclude:
                try:
                    del node_data[ex]
                except __HOLE__ as err:
                    logger.warning(err)
        if api:
            resp = self.app.post(
                reverse('NodeCollectionHandler'),
                jsonutils.dumps(node_data),
                headers=self.default_headers,
                expect_errors=True
            )
            self.tester.assertEqual(resp.status_code, expect_http, resp.body)
            if expected_error:
                self.tester.assertEqual(
                    resp.json_body["message"],
                    expected_error
                )
            if str(expect_http)[0] != "2":
                return None
            self.tester.assertEqual(resp.status_code, expect_http)
            node = resp.json_body
            node_db = Node.get_by_uid(node['id'])
            if 'interfaces' not in node_data['meta'] \
                    or not node_data['meta']['interfaces']:
                self._set_interfaces_if_not_set_in_meta(
                    node_db.id,
                    kwargs.get('meta', None))
            self.nodes.append(node_db)
        else:
            node = Node.create(node_data)
            db().commit()
            self.nodes.append(node)

        return node
dataset/ETHPy150Open openstack/fuel-web/nailgun/nailgun/test/base.py/EnvironmentManager.create_node