types.js

  /**
   * @record
   */
  var LocalDomWithBackground = function(){};
  /**
   * @type HTMLElement
   */
  LocalDomWithBackground.prototype.backgroundFrontLayer;
  /**
   * @type HTMLElement
   */
  LocalDomWithBackground.prototype.backgroundRearLayer;


  /**
   * @record
   * @extends PolymerElement
   */
  var ElementWithBackground = function(){};
  /** @type LocalDomWithBackground */
  ElementWithBackground.prototype.$;