**** CubicPower OpenStack Study ****
# Copyright 2010 United States Government as represented by the
# Administrator of the National Aeronautics and Space Administration.
# All Rights Reserved.
#
#    Licensed under the Apache License, Version 2.0 (the "License"); you may
#    not use this file except in compliance with the License. You may obtain
#    a copy of the License at
#
#         http://www.apache.org/licenses/LICENSE-2.0
#
#    Unless required by applicable law or agreed to in writing, software
#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
#    License for the specific language governing permissions and limitations
#    under the License.
"""Base class for classes that need modular database access."""
from oslo.config import cfg
from cinder.openstack.common import importutils
db_driver_opt = cfg.StrOpt('db_driver',
                           default='cinder.db',
                           help='driver to use for database access')
CONF = cfg.CONF
CONF.register_opt(db_driver_opt)
**** CubicPower OpenStack Study ****
class Base(object):
    """DB driver is injected in the init method."""
    
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    def __init__(self, db_driver=None):
        if not db_driver:
            db_driver = CONF.db_driver
        self.db = importutils.import_module(db_driver)  # pylint: disable=C0103