old_contents: # 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.
  
  from oslo_config import cfg
  
  from keystone.conf import utils
  
  
  driver = cfg.StrOpt(
      'driver',
      default='sql',
      help=utils.fmt("""
  Entrypoint for the domain config backend driver in the
  keystone.resource.domain_config namespace.
  """))
  
  caching = cfg.BoolOpt(
      'caching',
      default=True,
      help=utils.fmt("""
  Toggle for domain config caching. This has no effect unless global caching is
  enabled.
  """))
  
  cache_time = cfg.IntOpt(
      'cache_time',
      default=300,
      help=utils.fmt("""
  TTL (in seconds) to cache domain config data. This has no effect unless domain
  config caching is enabled.
  """))
  
  
  GROUP_NAME = __name__.split('.')[-1]
  ALL_OPTS = [
      driver,
      caching,
      cache_time,
  ]
  
  
  def register_opts(conf):
      conf.register_opts(ALL_OPTS, group=GROUP_NAME)
  
  
  def list_opts():
      return {GROUP_NAME: ALL_OPTS}
  
new_contents: # 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.
  
  from oslo_config import cfg
  
  from keystone.conf import utils
  
  
  driver = cfg.StrOpt(
      'driver',
      default='sql',
      help=utils.fmt("""
  Entry point for the domain-specific configuration driver in the
  `keystone.resource.domain_config` namespace. Only a `sql` option is provided by
  keystone, so there is no reason to set this unless you are providing a custom
  entry point.
  """))
  
  caching = cfg.BoolOpt(
      'caching',
      default=True,
      help=utils.fmt("""
  Toggle for caching of the domain-specific configuration backend. This has no
  effect unless global caching is enabled. There is normally no reason to disable
  this.
  """))
  
  cache_time = cfg.IntOpt(
      'cache_time',
      default=300,
      help=utils.fmt("""
  Time-to-live (TTL, in seconds) to cache domain-specific configuration data.
  This has no effect unless `[domain_config] caching` is enabled.
  """))
  
  
  GROUP_NAME = __name__.split('.')[-1]
  ALL_OPTS = [
      driver,
      caching,
      cache_time,
  ]
  
  
  def register_opts(conf):
      conf.register_opts(ALL_OPTS, group=GROUP_NAME)
  
  
  def list_opts():
      return {GROUP_NAME: ALL_OPTS}
  
subject: Improve keystone.conf [domain_config] documentation