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 heat.engine.resources.openstack.heat import software_deployment
  from heat.engine.resources.openstack.heat import structured_config
  
  
  class SoftwareDeployment(software_deployment.SoftwareDeployment):
      """A custom subclass to allow reverting replacement."""
  
  
  class StructuredDeployment(structured_config.StructuredDeployment):
      """A custom subclass to allow reverting replacement."""
  
  
  def resource_mapping():
      return {
          'OS::TripleO::Heat::SoftwareDeployment': SoftwareDeployment,
          'OS::TripleO::Heat::StructuredDeployment': StructuredDeployment
      }
  
subject: Add custom subclass to revert mapping