code: function digest(message) {
      return message.id || sha1(serializeNodes(message.nodes).join('') + ("[" + message.meaning + "]"));
  }
docs: @license
  Copyright Google Inc. All Rights Reserved.
  
  Use of this source code is governed by an MIT-style license that can be
  found in the LICENSE file at https://angular.io/license
   
  @param {?} message
  @return {?}