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 keystone import assignment
  from keystone import auth
  from keystone import catalog
  from keystone.common import cache
  from keystone.contrib import endpoint_filter
  from keystone.contrib import endpoint_policy
  from keystone.contrib import revoke
  from keystone import identity
  from keystone import policy
  from keystone import resource
  from keystone import token
  
  
  def load_backends():
  
      # Configure and build the cache
      cache.configure_cache_region(cache.REGION)
  
      # Ensure that the identity driver is created before the assignment manager
      # and that the assignment driver is created before the resource manager.
      # The default resource driver depends on assignment, which in turn
      # depends on identity - hence we need to ensure the chain is available.
      _IDENTITY_API = identity.Manager()
      _ASSIGNMENT_API = assignment.Manager()
  
      DRIVERS = dict(
          assignment_api=_ASSIGNMENT_API,
          catalog_api=catalog.Manager(),
          credential_api=credential.Manager(),
          domain_config_api=resource.DomainConfigManager(),
          endpoint_filter_api=endpoint_filter.Manager(),
          endpoint_policy_api=endpoint_policy.Manager(),
          federation_api=federation.Manager(),
          id_generator_api=identity.generator.Manager(),
          id_mapping_api=identity.MappingManager(),
          identity_api=_IDENTITY_API,
          oauth_api=oauth1.Manager(),
          policy_api=policy.Manager(),
          resource_api=resource.Manager(),
          revoke_api=revoke.Manager(),
          role_api=assignment.RoleManager(),
          token_api=token.persistence.Manager(),
          trust_api=trust.Manager(),
          token_provider_api=token.provider.Manager())
  
      auth.controllers.load_auth_methods()
  
      return DRIVERS
  
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 keystone import assignment
  from keystone import auth
  from keystone import catalog
  from keystone.common import cache
  from keystone.contrib import revoke
  from keystone import identity
  from keystone import policy
  from keystone import resource
  from keystone import token
  
  
  def load_backends():
  
      # Configure and build the cache
      cache.configure_cache_region(cache.REGION)
  
      # Ensure that the identity driver is created before the assignment manager
      # and that the assignment driver is created before the resource manager.
      # The default resource driver depends on assignment, which in turn
      # depends on identity - hence we need to ensure the chain is available.
      _IDENTITY_API = identity.Manager()
      _ASSIGNMENT_API = assignment.Manager()
  
      DRIVERS = dict(
          assignment_api=_ASSIGNMENT_API,
          catalog_api=catalog.Manager(),
          domain_config_api=resource.DomainConfigManager(),
          id_generator_api=identity.generator.Manager(),
          id_mapping_api=identity.MappingManager(),
          identity_api=_IDENTITY_API,
          policy_api=policy.Manager(),
          resource_api=resource.Manager(),
          revoke_api=revoke.Manager(),
          role_api=assignment.RoleManager(),
          token_api=token.persistence.Manager(),
          token_provider_api=token.provider.Manager())
  
      auth.controllers.load_auth_methods()
  
      return DRIVERS
  
subject: remove unused module references in keystone.backends