code: function templateServiceFactory(
      Constants, 
      Promise, 
      _, 
      DbRenderable,
      Util ) 
  {
      Util.inherits(TemplateService, DbRenderable);
  
      /**
       * TemplateService is a singleton object which provides key/value store
       * access to template files loaded from disk via FileLoader.
       * @constructor
       * @extends {FileLoader}
       */
      function TemplateService () {
          DbRenderable.call(this, {
              directory: Constants.Templates.Directory,
              collectionName: 'templates'
          });
      }
  
      return new TemplateService();
  }
docs: templateServiceFactory provides the template-service singleton object.
  @private
  @param  {FileLoader} FileLoader A FileLoader class for extension.
  @param  {configuration} configuration      An instance of the configuration configuration object.
  @return {TemplateService}            An instance of the TemplateService.