@mock.patch.object(sqlalchemy_api, '_create_facade')
    def test_create_facade_lazily(self, mock_create_facade):
        mock_create_facade.side_effect = [mock.Mock(), mock.Mock(),
                                          mock.Mock(), mock.Mock()]
        mock_conf_group = mock.MagicMock()
        main = sqlalchemy_api._MAIN_FACADE
        api = sqlalchemy_api._API_FACADE
        f1 = sqlalchemy_api._create_facade_lazily(main, mock_conf_group)
        print('f1 = %s' % f1)
        f2 = sqlalchemy_api._create_facade_lazily(api, mock_conf_group)
        print(f2)
        f3 = sqlalchemy_api._create_facade_lazily(main, mock_conf_group,
                                                  connection='db1://')
        print(f3)
        f4 = sqlalchemy_api._create_facade_lazily(main, mock_conf_group,
                                                  connection='db2://')
        print(f4)
        # facade for db2 should be cached and not created a second time
        f5 = sqlalchemy_api._create_facade_lazily(main, mock_conf_group,
                                                  connection='db2://')
        print(f5)
        self.assertEqual(4, mock_create_facade.call_count)
        # facades with different connections should be different
        self.assertNotEqual(f3, f4)
        # facades with same connection should be the same
        self.assertEqual(f4, f5)


f1 = <oslo_db.sqlalchemy.enginefacade.LegacyEngineFacade object at 0x7f5f6b17a978>
<Mock id='140047780217912'>
<Mock id='140047780219928'>
<Mock id='140047781833304'>
<Mock id='140047781833304'>