old_contents: /**
   * @license
   * Copyright 2017 The FOAM Authors. 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.
   */
  
  foam.CLASS({
    package: 'foam.box',
    name: 'Message',
  
    properties: [
      {
        class: 'Map',
        name: 'attributes'
      },
      {
        class: 'Object',
        name: 'object'
      },
      {
        class: 'Map',
        transient: true,
        name: 'localAttributes'
      }
    ]
  });
  
new_contents: /**
   * @license
   * Copyright 2017 The FOAM Authors. 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.
   */
  
  foam.CLASS({
    package: 'foam.box',
    name: 'Message',
  
    properties: [
      {
        class: 'Map',
        name: 'attributes',
        javaFactory: 'return new java.util.HashMap();'
      },
      {
        class: 'Object',
        name: 'object'
      },
      {
        class: 'Map',
        transient: true,
        name: 'localAttributes',
        javaFactory: 'return new java.util.HashMap();'
      }
    ]
  });
  
subject: Add java factories for Message.attributes/localAttributes to improve usability.